Hi Jason,
I think you'll be fine with X8 and 10. I did have to install a fresh copy of 10 as like others have said, the 'upgrade' to 10 is not without problems. That might have been some of the 'weirdness' you were experiencing.
Being cheap, I found a full licensed X6 CD on Ebay for a really good price. Was supposed to be 'new', but had some suspicious scratches, but was able to copy to disk using some special software my son uses at work for backups. Once it copied clean to disk, I was able to install and working fine.