You have not really described what you mean with "freeze", is it total hang, or is mouse and intuition alive?
I'd try to isolate the real problem first. Boot while pressing alt key to have loadwb skip wbstartup, and then check out the program in wbstartup, for example...
* do they start if you start them manually by double clicking them?
* do they have "Wait till finished" checked?
* are the protection bits sane?