Lockups while using - get BSOD

I suffered a problem where my computer would randomly just reboot. So I turned off Automatically restart in the tools menu.

I could be playing a game, using Windows Explorer, using Norton or whatever, and without warning get a crash to the blue screen. It isn't the same error message every time and I can't seem to consistently reproduce the error.

Here are my stats before I continue:
Asus P4B533-V Bios 1.004 - no overclocking settings
OCZ PC2700 Rev 3 with copper heat spreaders - 2 x 256mb sticks
SB Audigy with the latest drivers
Visiontek GeForce 3 Ti500 with the 30.82 WHQL Nvidia Ref.
2 Voodoo 2's (both are disabled and no drivers installed)
Adaptec 2940U2W using Aspi Layer 4.71 and 3.03 Family Drivers (actually I think for XP I didn't use the 3.03 since XP provides default ones)
Maxtor Ultra ATA 133

Now my crash issues also occur randomly in Windows 98SE (which I have installed on a totally different hard drive - use removeable IDE tray to keep any dual os problems from appearing )

Windows XP Home Edition (all patches up to but not including SP1 - waiting about a week or two longer before applying SP1).
All software and drivers are current as of September 2002.

I have looked at the MS Support site and their suggestions of what is the cause is like saying, well pick a part and we will blame it as the cause.

One message blames possibly the memory and video card. The next blames the sound card or memory. The only common thing of course is always the memory in all of this. But what is more perplexing, is I could run a graphic intensive game for 2 plus hours and not a single problem but run a less intensive game and it crashes in 5 minutes. Or I can play a game and suffer a lockup I restart and play the game and it doesn't happen again.

I keep my systems pretty much standard so the variables aren't changing constantly which would make it harder to troubleshoot.

Drives have been scanned for viruses and any problems in structure.

Here is a sampling of error messages from XP:
Driver_IRQL_NOT_LESS_EQUAL
Stop 0x000000D1 (0x0000010,0x00000002,0x00000000,0xF8287AEF
E100B325.SYS Address F8287AEF base at F8276000, date stampe 3c7a5e19

Another one was
PFN_LIST_CORRUPT
Stop 0x000004E(0x00000002,0x00005d19c,0x0001ff9,0x0000ffrf)

Now personally I find these so annoying as they say they are protecting either my software or hardware from damage, but every time they pull this lockup/bsod they risk damaging the system with not allowing windows to be shut down properly.

Now in Win98SE, when I play a game, it crashes to the desktop after 5 minutes or could be 2 hours of playing. It won't let me restart the game till I run Mem Turbo and defrag and clean the memory. Someone who knows about the game says the game is probably leaving behind parts in memory telling it to crash till they are cleaned out (like left over dll files common by older software).

I have run dxdiag and no issues and I ran the sound and video test to ensure they worked.

I tried today to crash my system using something that caused it to crash in win98se, running a full system scan. I put only one stick of memory in, and ran the scan and no crash. I then removed that stick (and yes I turned the power off ) and put the other stick in. That way I could at least determine if one stick or the other was defective. Result, neither would crash.

So my question then comes to what is the problem. These installs were clean and fresh. I also have two spare IDE's a 30 and 30GB, that I have winxp and 98se installed on as well, in removeable drives so that I can test. They also suffer the crash issues and they have just the barebones windows and minimal drivers or current drivers.

Now these same drives on my old motherboard worked, so I feel confident that isn't the issue.

And as mentioned I don't overclock anything, not even to the "official" settings that THG says the 845G supports in DDR333. I leave it at DDR266 settings. However I have it set to read the chip/memory chip settings. So could perhaps it read the chips at DDR333 level and be causing the instability? I ran Sandrasof and it reads the memory as only DDR266, so I don't think the board is reading it therefore as DDR333.

Now the item that makes me wonder is the APIC. In XP it sets every one of my add on cards (geforce, audigy, maxtor, usb, etc. all to above 16 including the nic that is onboard the asus p4b533-v). In 98 of course APIC isn't supported.

But is the APIC possibly causing problems with the settings in XP of course and for 98, the apic possibly causing irq conflicts as well, even though 98 isn't able to use the feature.

I dont' have the OS set to Plug and Play OS since I prefer to retain IRQ control (don't know how the Voodoo's would react to such management). I don't plan to probably run anything dos related, only cause a P4 2.4ghz 533fsb is a little too fast for any old dos games without slomo.

So any help on resolving these issues is greatly valued.