Someone tested it with Windows 7 and confirmed that the Editor worked (all the sub menus appeared). However they also stated that Aero was off. Perhaps having Aero off will solve the problem?
Although most likely unrelated, La-Mulana also has been reported with having problems with Aero.
From La-Mulana Wiki:
Windows 7 does not handle paletted games very well in fullscreen mode and will corrupt the color palette. There have also been transparency issues reported that may be linked to it but may be caused by Aero.
First try disabling Aero since if it enabled to see if it fixes transparency issues.
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RX-12 - Bydo Coefficient Test Unit
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Asker: How do I remove the border on a GroupBox in .NET?
Answer: Use a panel instead?
Asker: Gee, thanks @$$.