But, isn't that the result that you wanted - to make the Mail.app the default again?
Sounds like a good result, eh?
You didn't say if you tried the RCDefault.app this time.
Can't say about that bobsled extension, but maybe you can find it with a spotlight search, or you could try the find command in the terminal.
I found it and trashed it. No I have not tried that app. What does it do again?