WordPress, BlogJet, and XMLRPC

Setting up BlogJet, and I saw this helpful error:
Invalid Blog Response

Firing up a network sniffer, we can see that this (un)helpful error is actually a :
403 Forbidden

Digging a bit further, it seems some webhosts block access to XML-RPC.PHP.

One Solution: renamed the XML-RPC.PHP to something different.

edit: have also seen the error with Windows Live Writer.