I would like to use MSSQL too but I have some problems... for example, using the latest version available by CVS, I have this error:
 
APPLICATION ERROR #401

Database query failed. Error received from database was #0: for the query: UPDATE mantis_user_table
SET login_count=login_count+1
WHERE id='1'

 
It's very strange that the error is #0... I have tried that query on MSSQL using Query Analyzer and it's ok...
 
What is your experience using Mantis & MSSQL?
 
Thank you for your help.
 
Davide