Accessing OS X Leopard shares from Windows XP machine using Windows Sharing

I just upgraded from tiger to leopard and am having troubles with my Windows shares. On tiger I used sharepoints, which isn't leopard-compatible but did get imported to my leopard install. I removed the preference pane (and plist).

I changed the Workgroup name to the one used by the Windows machine.
I also enabled the guest account and allowed them to connect to shared folders.
In the sharing preference pane I enabled File Sharing, added a folder from my home directory, and made sure the user "Everyone" had read/write access. Besides that user, there is also my full name and my short name as 2 seperate users. When clicking options in this preference pane, "Share files and folders using SMB" is checked, as are the accounts appearing beneath it.
The firewall is turned off.

It is possible for me to connect to \\macName\shortName from the windows machine (after typing in my username and password). I am however unable to connect to \\macName\sharedFolderName. I get a password prompt (even though "everyone" has access) but can't use my shortname/password in it.

Any ideas what might be wrong?