What happen was Li Xiang was using my desktop half-way and the screen started to show grey horizontals lines and then some purple squares and finally it got so lagged that the computer restarted by itself. Tried several times to revived it, plug it out, clean the connector, waited for a few hours and put it back in again. But still no go.
Decided to drop Dennis  from Ban Leong a private message in Hardware Zone forums and he ask me to RMA it.
I seriously think that there is a problem with Leadtek PX9800GX2. My brother and I got the same computer at the same time on 8th May 2008 . My brother got a problem with his Leadtek PX9800GX2 in October 2008 where it could not display anything at all on his monitor. He also brought it down to Ban Leong for RMA. 9 months later, it became my turn instead.
Luckily for both of our cases, it is a 1 to 1 exchange maybe because they have stock for it. If not have to wait for 4 to 6 weeks as they will send it to Taiwan for repair. But of course the unit that they gave us is a refurbished one.
Anyway, here is Ban Leong address just in case you all could not find it.
Ban Leong Technologies Limited
No. 150, Ubi Avenue 4, Level 4 (SunLight Building)