No Standby in XP?

Installed XP Pro to dual boot with Win98. In “Turn Off PC” I have Hibernate, Turn Off and Restart but no Standby. If I disable Hibernate Standby is visible but greyed out and not selectable. I have APM enabled in Windows and ACPI enabled in BIOS. Standby OK in Win98. Running 600MHz Athlon on Asus K7M m/b. Had some problems with XP drivers for SB Live1024 soundcard, Mustek 1200C USB scanner and Rockwell 56K modem which are now resolved. I still suspect it’s a driver issue but don’t know what. Have posted this to various ng’s including Microsoft’s own but no luck so far. Any suggestions welcome.
Kenny