another GTK coexistence issue

greetings, everyone . . . among the applications that i absolutely need are the GIMP and the gthumb image viewer. since upgrading to 14.04 (both ubuntu and trinity), i've noticed that gthumb is working very slowly indeed, consuming vast amounts of processor. so i started it from a command line and it is throwing many errors, from which i find no hint as to the way to repair: dep@dep-desktop:~$ gthumb (gthumb:7260): Gtk-WARNING **: Failed to register client: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name org.gnome.SessionManager was not provided by any .service files (gthumb:7260): Gtk-WARNING **: Theme file for default has no directories (gthumb:7260): Gtk-WARNING **: Theme file for default has no directories (gthumb:7260): GLib-CRITICAL **: Source ID 187 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 193 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 197 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 200 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 203 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 206 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 209 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 212 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 215 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 218 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 221 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 224 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 227 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 230 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 235 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 238 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 241 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 244 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 247 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 250 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 253 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 256 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 259 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 262 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 265 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 268 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 271 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 274 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 277 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 280 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 283 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 286 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 289 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 294 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 298 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 301 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 304 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 308 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 311 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 314 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 317 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 320 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 323 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 326 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 329 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 332 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 335 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 338 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 341 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 344 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 347 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 350 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 353 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 356 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 359 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 362 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 365 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 368 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 371 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 374 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 377 was not found when attempting to remove it (gthumb:7260): GLib-CRITICAL **: Source ID 380 was not found when attempting to remove it i suspect that the solution is as simple as installing a package, but i cannot imagine which one. any one here see what i'm missing? -- dep The shortest distance between you and playing great acoustic guitar: the great new instructional DVDs from Marjorie Thompson, available at www.MarjorieThompson.com