Today, for the first time, I experienced timeout errors with netTiers. The error I was experiencing made it impossible for me to use Sql Server Management Studio to open the locked table in question. To fix the SSMS locking issues, I followed the advice recommended in the article at http://sqlserverpedia.com/wiki/SQL_Server_Troubleshooting_Tips_and_Tricks#Query_Execution_Settings. In short, I needed to fine-tune my query execution settings to ensure that the lock timeout was some reasonable number (under Tools | Options… | Query Execution | SQL Server | Advanced).
I have been able to work around the problem (or at least, access the data via a netTiers-generated website) by taking the step outlined at http://community.codesmithtools.com/nettiers/f/16/p/10414/39181.aspx#39181.
Specifically, I ran the following code before any other queries were executed against the database (eg, in your master page or global.asax):