In 2 PCs, using kde-testing overlay: emerge =koffice-libs-1.9.98.5 (or any koffice app) fails around 19%. googling (since I don't have the knowledge to properly track the bug) I've found a guy that says "To compile with 4.2RC1 and onward, you need to apply the attached patch to beta5." Applying that 1 line patch solved the issue. I tried to do it modifying the ebuild, but it was although beyond my current skills, I'll be trying again later. I leave it here as an attach. Sorry for the bad english and bug-report.
Created attachment 181384 [details, diff] Patch for compiling koffice-2 beta (1.9.98) under KDE 4.2
Created attachment 181440 [details] Fixed Ebuild A fixed version of the kde-testing ebuild
I will do a bump at some point this week, where it is fixed. Closing this one as wontfix, please stay tuned for commits on overlay or use 9999 ebuilds.