Thanks for your time!
Turns out the fault was all mine. When I switched servers, I forgot to install php5-gd. What’s weird though, is that there were no errors, neither in WordPress nor in the log files.
Anyway, issue is fixed now. Thanks again.
I’ve talked with Michel Valdrighi on IRC and he said 1.5.1 is on it’s way. I don’t know when it’s due but it’s surely coming. So I’ll just wait.
Ouch, obviously right after posting I noticed that someone else is having the same problems.
Here – http://wordpress.org/support/topic.php?id=23891
