I'm using Gentoo 2.4.26 with KDE 3.3.2 and xorg 6.8.0-r3 and am having problems with X using all available cpu power when connecting to my laptop with KDE Desktop Sharing.
Steps for reproducing:
1. Start KDE Desktop Sharing
2. Create a personal invitation
3. Connect from other computer using TightVNC or RealVNC client on Windows XP SP2.
4. Accept Connection on host
5. CPU usage on host jumps to ~100% immediately, even before typing in the password on the client side. If I cancel the connection on either end manually or by timeout the cpu usage drops to a normal level.
Using top I see that 'X' and 'krfb' each use about 47% each, with a second 'krfb' using ~5%.
If I rather use vnc-3.3.7 which afaik. has its own XFree server it works like a charm and is lightning fast, but I'd rather have the same view on both ends since I also use it as a means of using the same keyboard/mouse as my main computer. Besides, having something not working perfectly is like an annoying thorn in the side you just can't get out yourself :-\
I originally had Xorg 6.7.0-r1 installed and upgraded to 6.8.0-r3 in the hopes that would fix the problem.
I've searched the net a bit and have only found a few cases with a similar problem. Most notable was this case from the forums of Novell:
Subject: KDE desktop sharing use 100% of the CPU all the time
But as of now there's no answer. Note that his top statistics are very close to mine, and could probably be considered equal as they're not completely stable and it all depends on which seconds snapshot he got :-P
Soo... I'm lost