If you are using Threat Management Gateway (TMG) with Service Pack 1 (SP1) installed and have configured SQL Server to store the TMG logs, then you may see that the TMG cannot insert the logs into SQL Server logging database. This issue happens if the logging database name contains special characters such as dashes (-) or underscores (_). At the same time you may see an increase in the log queue, for example:
To workaround this issue, you may want to use only letters and numbers in the database name, such as TMGLogDB, instead of TMG-LogDB until a fix is available.
TMG 2010 with SP1