SQL Server 2005 Hanging - Selecting Uncommitted Data

We have found an issue with using MSS 2005 with odbc connections, some of
our code inserts data, then reselects the data back with a select using a
different handle. This hasn't caused any issues before but in one customer
this causes a lock up. The timeout error doesn't occur as you would expect
if trying to select data that is uncommitted by another user.

Although obviously we could re-code to avoid selecting uncommitted rows, can
anyone tell me why this works sometimes but not others. Some kind of
setting in MSS that we're unaware of maybe. The code works ok on other MSS
2005 & MSS 2000 servers and oracle & sqlbase.