freebsd stable - Feb 2011 - FreeBSD 8.2-RELEASE amd64 Gnome and KDE Slowness

I have installed FreeBSD 8.2-RELEASE amd64 on an Intel DG965WH mainboard
with 6 GB RAM , 500GB Seagate HDD .

When GNOME or KDE is used , their start times are very long as spanning many
minutes , and opening of menus in applications such as Firefox , Dolphin ,
and their other programs  are taking many minutes to just open the menu .
Clicking any item , is also waiting many minutes to be activated .

In that structure , it is not possible to use those desktop environments .

After that , I have installed FreeBSD 8.2-RELEASE i386  on the same computer
. The same actions are performed instantly .

After that , I have installed PC-BSD 8.2-RELEASE amd64 . It is just like
FreeBSD 8.2-RELEASE amd64 : Extremely slow .

On FreeBSD 8.2-RELEASE amd64 , I have installed FluxBox . Its menus and
their items are executed very fast .
When a Gnome or KDE ( Dolphin , Ark , K3B ) program is executed from FluxBox
, their menus are again very slow ,
whereas Firefox , Midnight Commander executions are very fast .

This case is just related to FreeBSD 8.2-RELEASE amd64 . The other 64-bit
operating systems are working very well .

I have tested memory chips : There is no any error .
I have used another 500 GB Seagate HDD : Effects are the same .


I could neither be able to understand why this is happening , nor find a
cure to this problem .

Thank you very much .

Mehmet Erol  Sanliturk