Control keys do not work across a VNC session. There may be other keypresses which are not working but ^c ^v etc are the ones that are biting me in the $*^*! presently. This problem exists with x11vnc and tigervnc so is probably related to something they both link against. I cannot verify if this is also an issue with tightvnc because this package will not emerge.
Try finding a bug first, maybe on the forums or IRC or a mailing list.
i know of no upstream bug reports related to this as i have no idea where the problem lies exactly. ossman in #tigervnc (freenode) says there can be issues like this if the client in being used is linked against a version lf FLTK that does not have some "patches" applied. info on these patches is given in .http://sourceforge.net/p/tigervnc/code/HEAD/tree/trunk/BUILDING.txt
