It turns out this was an error on google's part. The problem was promptly fixed and here is what they had to say.
" A bug recently caused some minor corruption in our datastore, causing 0.0003% of the files in our Subversion repositories to be unavailable. Unfortunately that included a few files from the trunk of the plsnpairs project. I've repaired the Bigtable and you should now be able to check out your project. Sorry for the inconvenience! "
