Yea - know exactly what ya mean, have to reinstall OS to get the new BIOS settings to take effect...
Hope you dont have the same problems with your BP6 I had with my BE6-II. IF it has the HPT66 UDMA IDE controller your going to be turning that manual shutdown right back on!
The UDMA66 controler, which isn't native to your 440BX chipset, indroduces some odd behavior. THE HPT66 shows your IDE disks as SCSI.. and gray out the enable cache checkbox. Look at Disk Drive in Device manager. I used to have trouble with the machine shutting down so fast the the disk cache write wasnt complete when the power shutt off!!! Next start I had CORUPTION!!! Wouldn't boot... I went back to NO ACPI, No APM so it didn't power off so fast - never had a problem since...
And the problem won't show up until you have a full load of software on the box and the registry starts getting pretty big(registry ans sys stuff are the last things to get written to disk on shuttdown, thus the exact things that get corrupted with a fast power down)
My BE6-II ran Win 2000 quite good. I kept puttin more software on it until one day - Whack - Corrupt boot! After repeating the sequence acouple times I could literally see the IDE activity light was still on when the box powered down. OOPS! I went back to NO APM and the problem has never happened again. Yea, I get the "The computer is OK to Shut off" message and have to push the button in fo 5 seconds - but it's stable as a rock(for a long time now)
If ya have a HPT66(High Point Tech) UDMA66 controller on your ABIT MoBo - beware- you've heard about the problem(Search forum for HPT66).
Hope ya don't! First ya update the BIOS and reinstall to get it to APM shutdowm(you've allready done that) - Then ya have to change the BIOS, reinstall to get it to take effect so not to powerdown too fast just to get it to be stable... ABIT and HPT66 aren't on my favorite list anymore - from experience...