Strange goings on with upgrade

Just upgraded to 1.5 today. Loving it. Thing is, having one or two teething problems over at http://www.wanbro.com/blog

1. When I log into the dashboard, all is good, until I click Options>Discussion, when I’m greeted with:

“No input file specified.” and a blank page.

2. People are able to write comments under my name and identity. (see here: http://www.wanbro.com/blog/?p=377#comments)

Clearly something’s up with the comments, but I followed the instructions to the letter… what’s going on?!?!

Thanks in advance.