Loading page after deleting datastores throws error because memcache still persists user info for 6 minutes

[GoogleCodeExporter]

What steps will reproduce the problem?
1. Build & deploy
2. Using Datastore Viewer, delete all tables except AwsAccountDetails
3. Reload your QBot instance home page and try and enter URLs

Expected
Allow user to enter URLs as they had done previously

Actual
Errors about BotsUser not existing in the logs because Memcache does not expire 
for 6 minutes.

What version of the product are you using? On what operating system?
r12
MacOS 10.6.8

Please provide any additional information below.
If you wait 6 minutes the problem goes away

Original issue reported on code.google.com by [email protected] on 3 Nov 2011 at 11:13