Delete mame.ini
From command line from the mame directory, type "mame.exe -cc" to generate a new one.
Open VMMaker, open config, check last tab, make sure "export monitor settings to Groovymame" box is checked and your mame.exe is selected. Click OK.
Take notice of the message "Exporting settings to mame.ini...".
If you have your roms in a non-default location, you may need to update the ROMS directory.
If that doesn't work then generate a log file. Instructions are at the bottom of all Calamity's posts.