Confirming this problem...
Ubuntu Edgy 2.6.17-10-generic #2 SMP Tue Dec 5 21:16:35 UTC 2006 x86_64 GNU/Linux
Context switch from Firefox (both Ubuntu package 2.0.0.1+0dfsg-0ubuntu0.6.10 and Mozilla build 2.0.0.1) to Xterm results in 100% CPU by Xorg (7.1.1ubuntu6.2).
Confirming this problem...
Ubuntu Edgy
2.6.17-10-generic #2 SMP Tue Dec 5 21:16:35 UTC 2006 x86_64 GNU/Linux
Context switch from Firefox (both Ubuntu package 2.0.0.1+ 0dfsg-0ubuntu0. 6.10 and Mozilla build 2.0.0.1) to Xterm results in 100% CPU by Xorg (7.1.1ubuntu6.2).