another probably stupid question

hi, everybody . . . one of the few applications i find absolutely essential is the gthumb image viewer. it's a gnome application, and i have for many years run it from the trinity desktop uneventfully. with my recent upgrade to ubuntu 14.04 from 12.04, gthumb has become really, really slow. things like 30 seconds to load an image, when previously i could click from image to image in a second or less. what makes it a puzzle is that on my fairly old (thinkpad x200) notebook, running 14.04, same trinity, same gthumb, it rips right along like always. i don't know whether on my desktop machine there's some battle between gnome and trinity stuff or just what -- don't even have a clue where to start looking. though i wonder if this might provide a hint. just did an apt-get dist-upgrade and hit this: Unpacking nvidia-opencl-icd-384 (384.90-0ubuntu0.14.04.1) ... dpkg: error processing archive /var/cache/apt/archives/nvidia-opencl-icd-384_384.90-0ubuntu0.14.04.1_amd64.deb (--unpack): trying to overwrite '/etc/OpenCL/vendors/nvidia.icd', which is also in package nvidia-opencl-icd-375 384.90-0ubuntu0.14.04.1 dpkg-deb: error: subprocess paste was killed by signal (Broken pipe) there may have been a time when i knew how to fix this, but if so i've forgotten. anybody know a fix? -- dep The shortest distance between you and playing great acoustic guitar: the great new instructional DVDs from Marjorie Thompson, available at www.MarjorieThompson.com