It reminds me of something...
I used to own a Minimig but sold it back because my monitor wouldn't accept its 50 Hz output (and I wasn't satisfied by the 60 Hz mode). What puzzled me is the fact it did accept a 50 Hz output from my "internet provider TV Box" (how do you call that in English ?).
There are probably tons of differences between those 2 devices... Different resolution but also the fact that the former was using a VGA plug and the latter an HDMI one.
Any idea ?