Hi, I am facing similar problems with one of my new blogs — can’t delete comments and can’t delete posts. But I’ve managed to resolve the problem.
This is the process I’d go through again if I ever come across such a problem: Log on to the blog host’s control panel (CPanel), click MySql Databases, choose the database of the “faulty” blog, click “Check DB”. Then after Check DB is done, click “Repair DB”.
I don’t know about other blogs but this solution works for me. — Jaxon S
http://macro-photography-blog.com