djmax,
Looks like there is a problem with web.py,
Could you provide some information about what occurred before the error messages?
Was this a new install or an update from a recent version?
The easiest fix would probably to just re-install:
http://rayshobby.net/mediawiki/index.php?title=Python_Interval_Program_for_OSPi#From_an_older_version_not_installed_using_git
I have tested the update and a new install and they both worked.
Dan