Hi everyone,
I am solving this problem: I am developing webPart (Visual Studio 2008) and I want to connect to the SQL database (2008) but somehow I get this error at SharePoint site (2007):
Login failed for user 'umsreader'.

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.Data.SqlClient.SqlException: Login failed for user 'umsreader'.

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

When I use Widows authentication I also can't connect to the database. But when I create ordinary Web application everything work fine, just when I use this at Web part at Sharepoint.

I tried change web.config, but it is still the same. I really don't know where problem could be :(