Help: trying to stay with 2.5 Build for now!

There have been so many problems logged with 3.0 that I would like to stay with 2.5 for now. I have several old installation packages, labeled builds 3188, 3212 and 3214. Does anyone know what these builds do? Specifically, do they install full-fledged 2.x builds, or do they install some form of upgrade version of 2.x that prompts you to upgrade to 3.0?

Also, I have read that build 3188 has some serious problems of its own. Should I consider an even earlier version of Parallels?

Thanks...