After checking out a Visual Studio 2008 solution from our Subversion repository to a new machine (and new physical location) I started getting failure on the post build event reporting an exit code of 9009. As ever it was building fin on another machine (luckily for once this failure wasn't on the continuous integration server).
With an exception like that It would have been easy to go off on one! This project had some post build processing running in batch file, including RegAsm! Looking at the simple things first, it had been checked out to a location with long file names such that the batch file was not running correctly.
Just wrapping the command in quotes sorted it.
Ridiculously simple I know, but I thought I would write this one up - the way this was reported you could easily burn an hour or so chasing your tail...