I tried a complete reset and loaded the latest v1.2 software. It has improved slightly as the AVFourm podcast starts after a few attempts and then plays OK. I have the same problem with MacCast podcast which also uses the enhanced podcast format.
Obviously an iPod issue, that Apple don't appear to be able to fix.
Just like to say the Toshiba interview on #14 was really excellent, nice to hear a straight talking interview from a major manufacturer.