I only now upgraded my laptop's installation of MediaMonkey from one of the 3.x versions to 188.8.131.526, and have found an issue with the location of the database and settings used for MediaMonkey (non-portable installation). I am running under Windows Vista.
I understand that MediaMonkey version 4.x is supposed to keep its settings and database in %APPDATA%\MediaMonkey, which on Vista is by default C:\Users\<Username>\AppData\Roaming\MediaMonkey
However, on my computer, I have configured the Roaming folder to be in D:\AppData\Roaming instead, for ease of backup (D: is volatile data that gets backed up every week minimum, C: is executable or non-changing data that gets backed up every month or two). I've done similarly for the Local folder. Note that this is fully supported by Windows Vista, it's not a "hack" or anything else I would not reasonably expect a developer to support: you can easily change the location of AppData\Roaming and AppData\Local by opening up the folder properties for each one and going to the "Location" tab (along with moving the files, since Windows doesn't do that for you).
However, MediaMonkey 4 does NOT honor this setting, and instead seems to have hardcoded the use of C:\Users\<username>\AppData\Roaming and likewise for Local. MediaMonkey 3 DID honor this setting.
It's a minor bug, but one that is easy to fix correctly (the environment provides the APPDATA variable, which should be accessible from the WinAPI) and that MediaMonkey 3 did right. For now, I've just routed symlinks to the correct locations, but it would be nice to see this fixed—if this had been a clean install, not an upgrade in which I noticed my old database wasn't imported, my MediaMonkey library would've fallen right under the radar!