I installed Desktop Drapes to get rotating backgrounds. In the program's preferences you can check to have it start on login, which I did. I then opened up Startup Applications to double check that it was included there, which it is. But it does not start on login. It works fine when I manually start it.
Running Mint 11 64-bit on a Lenovo ThinkPad Edge E420s laptop (quad Intel i5-2410M CPU @ 2.30GHz, 8GB RAM).