Sometimes may happen in a database there to be fields with different Collations and it will make you problems. Previously i wrote about a way to get over this issue directly in your queries. Other option is to change the collation on the sql server for that "problem" column.

Here is an example of how to do it:
Alter Table yourTable

Alter Column yourColumn varchar(1000)

Collate Latin1_General_CI_AS

Easy