I've read that on Windows Server 2008, raising the DFL can cause XP and Linux/rdesktop clients to not be able to connect, but only if Network Level Authentication is enabled. However, we're only on Windows Server 2003 SP2, which doesn't even have the option to enable NLA, IIRC. So I thought we'd be safe.
I went and upgraded our DFL to Windows Server 2003, and now I can't log in via remote desktop. The error message, which appears almost immediately after clicking, is:
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Remote Desktop Connection
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This computer can't connect to the remote computer.
Try connecting again. If the problem continues, contact the owner
of the remote computer or your network administrator.
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OK Help
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Is this a coincidence, or did the DFL raise break RDP? (I didn't see any warning about this in the documentation.)