On Slackware 13.1 32-bit, I built opensync 0.22 and
tdepim with kitchensync enabled. No build problems with either.
I have not yet tested on Slackware 14.0 64-bit or with
a development version of opensync (0.3x).
The KDE3 version of kitchensync will compile against opensync 0.36 (it may need a patchset whose contents I didn't actually check), but not against 0.38, per https://bugs.gentoo.org/show_bug.cgi?id=262397 .
Unless someone has patched this further for Trinity, we may have a problem with opensync 0.39.
Oh, okay, so now we know the cutoff point. I will try testing with 0.36 and 0.38/0.39.
Darrell