Easy solution to the jazz songs problem:
- Create 1 new playlist in iTunes perhaps called non-Jazz.
- Drag ALL of the songs you sync to your iPod EXCEPT the jazz songs you hear all day at work into that new playlist.
- Sync the new playlist to your iPod so you can access it.
- When you get home, shuffle play the songs in that new playlist.
You won't hear any of the songs you play all day because they are not in that playlist.
Any whines about the randomness of shuffle isn't going to move Apple to go back and rework an algorithm on a dead product line. And all you are going to get here is the fans making you out to be the problem ("it's working exactly as it should", etc) vs. a few others chiming in some "mine too and it's frustrating." So just work within the system that you
can control. The playlist approach will eliminate having to hear the songs that you hear all day but are excluded (by you) from that new playlist.
Or if you do want to hear a subset of jazz favorites, drag them as individual songs into the playlist. If the bias is real, they may play more frequently than what random implies but you can always boot them back out of this playlist if you tire of them.
If it was me, I'd probably create 3 playlists: Work, Home, Combo or Hybrid. Work songs in Work. Non-work songs in Home. A little of both (hand picking favorites from both pools) for Combo or Hybrid (for when I am willing to hear some of the songs at work at home too). Then, just select a playlist & shuffle accordingly.