You mentioned that this happened after a hard reset, many things could have happened to a) cause your PC to freeze in the first place (i assume this is why you hit the reset switch) and b ) any number of things could have been happening when you did. I'm sure you are aware, as you seem like a guy who is tech savvy, that everyone's system is unique for the most part so trying to solve this anomaly could end up in an endless loop of "who's, why's and what if's". In this circumstance i would suggest you re-compile/re-install MAME first, as it seems from a third person point of view, this is where the fault lies. Then if you get the same results the staff will know to look into it further. You may find that a brand new MAME solves it - it may have become corrupt somehow, these things happen - especially after a hard reset, not just with emus/GE but all programs in general