Hi Calamity,
Is it possible to incorporate your Windows 7 ddraw resolution switch fix into other builds of MAME. Reason being is that, whilst Groovymame is my main build that I use for my cab, my friend and I like to play online with each other via our cabs using Mamehub which uses its own MAME build called CSUME.
Since I have an AVGA I use the AVRes app to generate ini's for each game which allow res changes for CSUME. Only thing is that I have to switch to a progressive resolution prior to running CSUME so I don't get the ddraw error. The issue with doing this is that being in a progressive resolution such as 288 lines makes using the Mamehub front end impossible since it doesn't scale well.
Therefore can your fix be applied to CSUME or is it unique to switchres only? I wanted to attempt this myself as I know you won't have the time for it. Are there alternatives?