Ok, so before re-installing, I tried to run the uninstaller, and it wouldn't work, and since there had been so many issues, I figured the best way would be to remove all files, and then go into registry and manually remove any entries for PSO. Just went into regedit and looked for anything with Sonic in the name. They all seemed to be under folders "Software" > "Sonic" and sometimes with sonic + other words. Anyway, I cleared all info regarding PSO and did a fresh install after clearing registry. Then proceeded to setup everything exactly as I had previously (turn on DEP, allow through antivirus etc). Just finished a roughly 3-4 hour gaming session with 0 random crashes. Wonder if it was just registry issues messing it up, and uninstalling-reinstalling wasn't enough? Guess only time will tell.