I am seeing this, too. A new OOTP 9 league, changed structure to 2 subleagues with 1 div each, 6 teams in each subleague.
I've got roughly 40 blank logos. I'm pretty sure I hit the "randomize" a couple of times before I settled on my teams & mascots.
As with others, these are regenerated at launch even if I deleted them.
I'm on a Mac (OS X 10.3.11, 1 GB RAM, 1.67 GHz G4 PowerBook).
Obviously this isn't the biggest bug. But it does make my images folder messy. Waaaaah!
