We are using 1and 1 and we have upgraded to the latest Moodle 1.2
Now we are having the same problems, 500 errors. I know there are topics elsewhere on this site about this.
In fact, if you create an assignment, get the error then look at the course, you can see the assignment is there but the details are missing. Go into it to edit, save and it all comes back and works properly.
This is not very satisfactory at all. Does anyone know the cause of this, or a fix?