When I put the iPod on shuffle, it seems to have some favourite songs that it plays loads more than others, and some that it never plays.
Am I imagining this?
It's probably because the software has been poorly written. The generation of truly random variation is actually enormously difficult and complex. Entire books have been written on this subject alone.
I suspect that you're not imagining it. The software is most likely at fault. Without wanting to start an Apple debate, I have always considered...
Mine does it too. It's almost as if it has it's own favourites that it likes to play and others it obviously doesn't like that it simply refuses to play at all.