Memmory refrence errors are caused by hardware (9/10 times) Thats all I can tell you and there are no working hacks for pbo atm.
Might wanna open your pc make sure everything is plugged in tight. Check temp on your ram and cpu when running High end graphics games.. (hint let it get hot first make sure your not over heating in mid game play. signs of this is decreased graphics card performance the longer you play..)
Theres alot that could be wrong with memmory reffrence error tho.. A memory reffrence points to a dump file produced by windows based on the error thats where info lies. However unless you have the books every computer engineer carries with them you are clueless cause there isnt anything on the internet for these type of errors but people looking for help like you and not getting it. They explain all the dump errors in detail and you wont find them anywhere on the web. Hell, I dont even know where to get em..
There are special software disks you can get that will scan your hard ware for you and give you feedback on whats wrong but if you scan on a cold start it wont find nothing you wanna scan while you got it running hard stuff or right after..
Sorry if this didnt help you I was bored so I figure I would explain it a lil for you.
I had a pc that had mem ref errors while playing games for 3 years BELIEVE me I looked for the answers they aren't there to be found..