Drive mapping fails via GPO preferences but works fine in a VBScript

I'm running a few Windows Server 2008 R2 servers with domain computers running Windows XP SP3. Client side extension is installed.

I opted to use Group Policy Preferences over the conventional VBScript to map drives but it keeps returning an error code 0x80070035. I have no idea why this is happening as I can access the shared folder from the explorer once I log in. Furthermore, it works fine when it's mapped via a login VBScript!

Maps as action "Update" on drive "P:" on "\SV-APP-001\Public Share\", Reconnect enabled.

I'm 100% sure the group policy is applying correctly as I've done a GP Results run and it's also spitting the error into the events log on the workstation.

Other things I've tried:

• Allowing the SYSTEM account full access to the share.
• Changed the path to an IP instead of the computer name.
• Ticked the "Run in logged-on user's security context" option.
• Slam the keyboard into the screen in frustration.

Any other suggestions or ideas?

It seems drive mapping doesn't like trailing slashes on the UNC path! Took me 3 days to figure this out the hard way.