We migrated our DNN 6 site from a 2003/II6 box to a 2008 R2/II7.5 box.  After a few adjustments, everything seemed to be working OK, execept we cannot log into the DNN site.  For the migration, we setup an empty IIS site and copied over the DNN file structure from the old box.  We made some adjustments to security settings in IIS and the site was working.

When we attempt to log into DNN, we get the following error logged in the event log (DNN just goes back to the page as if you're not logged in):

Event code: 4006
Event message: Membership credential verification failed.
Event time: 4/4/2012 10:50:28 AM
Event time (UTC): 4/4/2012 3:50:28 PM
Event ID: 0e6c8c26f9244c599531a46299ce74c1
Event sequence: 2408
Event occurrence: 1
Event detail code: 0

I found a couple of other posts with similar problem, but the resolutions didn't seem to apply or I couldn't find what they were referencing.

Anyone have any suggestions on where to look to fix this particular issue?

Thanks