Hi Phil,
It sounds like you may be running into two issues.
1. The corruption error is caused by non English-US regional settings. This is scheduled to be fixed, but in the mean time set your service accounts to run as English-US without impacting the actual end-users. Steps are listed here:
http://social.microsoft.com/Forums/en-US/managementreporterBeta/thread/1b2e0ea0-a9cf-4acd-b95a-b785198e7cee
2. The Migration Wizard stopped working when we went from Beta to RTM. Once you fix the first error you can manually create reports, wait for the update to come out shortly to fix this issue, or roll back to MR Beta to perform a migration.
My apologies on hitting a few different issues.
Thanks
Ryan