I just did a fresh 10.1 install and wiped out my old and messy 10.0 on my drive. And I started to use fluxbox as default WM. At the VERY FIRST BEGINNING, when I 'startx', fluxbox comes out without any hesitation. However, when I just try to compile 2.6 series kernel in CLI ONLY and 'startx' afterwards, fluxbox starts running slow. It appears after 10-15 seconds, at least. I cannot figure out why. I just 'top' in CLI to locate the problem. Found X11 uses up 9x& of CPU time, so I check /var/log/messages, /var/log/Xorg.0.log and 'dmesg'.
Only message from dmesg
EE) GLX is not supported with the Composite extension
Other has no messaged related to X11.
Anyone can figure it out why?
Note: I should have posted it to Software Forum, but the power of Slack Community is so great that I may seek more help here.