There are two categories of Metabase corruption:
- Structural corruption
If you want to check your Metabase for structural corruption you can do this very quickly by trying to open it with Metaedit 2.2 for IIS5 or Metabase explorer for IIS6.
NOTE: If you have a Windows 2003 server in your domain you can install Metabase explorer on it and open remotely both IIS5 and IIS6 metabase. You can download Metaedit 2.2 from here
and Metabase explorer from here
- Logical corruption
Enabling Diagnostic logging for MSExchangeMU (Metabase Update) to maximum can give you more information about sync errors between AD and the Metabase.