Tortoise SVN does not ask for user/pass and fails

I installed tortoiseSVN and was able to do a checkout of the dirs/files that are already in the repository (I don't need to authenticate for that) When I try to commit changes I get the following error:

Server sent unexpected return value (403 Forbidden) in response to CHECKOUT

I am never asked to enter my user/pass for authentication.

Tried googling it a bit, and found various mentions of this, but no definite answer. I talked with the people in charge of the SVN server on our campus, and they claim that everything is OK on the server side...

Any help would be greatly appreciated :)

Yair

From stackoverflow

• I am going to assume that you talk with the repository over http or ssh.

  You can then write the repository address this way: protocol://username@machine-address/repository-dir. This should force tortoise to log you in.

• Maybe TortoiseSVN uses some saved authentication data that is no longer valid?

  Try deleting any saved authentication data in TortoiseSVN's the settings dialog (under "Saved Data"), then retry committing.

• Maybe you must remove the preceding spaces before the account/password settings in the config file(s) of the repository.