Hi, I made a patch for this bug: http://bugzilla.gnome.org/show_bug.cgi?id=121788 Basically its just the screenshot.c from 1.3.19 but it fixes the mentioned problem and could be used until the Gimp team releases a offical fix with the next development version. Patch was successfull tested on Sparc.
Created attachment 18385 [details, diff] Patch for screenshot.c ... put into files/
Created attachment 18386 [details, diff] Patch against ebuild
patch in 1.3.20-r1 , thanks for the report.