http://www.jetway.com.tw/evisn/downl...os/index-1.htm - are you up to the latest available motherboard BIOS (A15 - 12/20/01 for the 663 AS/Pro) ?
Is the PCI card still in place when you try the AGP?
It SHOULD be possible to use a an 8x capable card in a 4x slot - and ATI's chart has the 9200 as being compatible with 2x (3.3v), 4x (1.5v) and 8x (0.8v) signalling - one place older motherbords often fall down on, is AGP slot power requirements - as these tend to be uprated from standard to standard - I presume this card does not have a molex power feed?