Problesm adding forms to sites

Problesm adding forms to sites

Any suggestions why I can't add any type of form to my site. It only turns up with "Error in creating form, Try again".

And a bonus question. Why can't I delete and old site from "Manage sites"? I have one that hasn't got a name, which I can't delete. Why would I delete it then, just because I like things to look right :-)