Any way to tell if a disc was burned in UDF or ISO mode?

[Shudder]

My dvd player plays divx files and some of the discs, even scratched, are flawless. Some aren't. They're read on the PC just fine, have no errors, but skip like mad on the Set top.

I read on one of the pages about it that it didn't like things in UDF mode and I MAY have burned some with it instead of ISO. Is there a way for me to check now that the disc is already burned?

[Cornucopia]

ISOBuster

[HyperYagami]

or DVDInfoPro