I have been having the same problems with my AMD 1.0ghz on an AOpen AK73 Pro Socket A Board. I ended up cleaning off the hard drive and installing a full blown edition of XP Pro. Well, same old thing. Lockups, freezes, defrag lockups, etc.
I checked with esupport.com who are familiar with my Flash BIOS.
A phone call today confirmed my suspicion that the BIOS was up to date, even though its 4 years old, with the MoBo but not with Windows XPSP2. An updated BIOS supposedly will allow XP and XP Pro with SP2 run without the lockups and freezes.
I'll probably be doing the upgrade after I find out how fast of an AMD Processor I can put on the MoBo. Again, the BIOS upgrade is supposed to also allow me to run an AMD 2200 Processor on a MoBo that I can only do 1.4ghz on right now with the current BIOS.