Re: Booting from DVD...
I gotta' question- why not just use onboard?
Regardless- to do a fresh OS install you don't just select custom. You have to delete the old partition, create a new one and format it, then proceed with the OS install. This will remove *everything* on the hard drive though.
As to the issues, unsure. I've always loathed Creative's drivers. Maybe go back and try some older versions? See if those will work?