The fix is easy: Two #include's have to be added. Patch is attached.
Created attachment 190864 [details, diff] Fix compilation with gcc-4.4
As an alternative, octave-3.0.5 is out since weeks ago, and it fixes the bug: http://bugs.gentoo.org/show_bug.cgi?id=264757
I've just added octave-3.2 to the tree which should fix this. Thanks much for letting us know. Best, Markus