Hmm I can start 1942.zip, but Simpsons crashes on my Vita when I try to load it (mame 2003 0.78 romset, used to work fine in older Retroarch).
I tried the stable 1.6.9, both the version from retroarch.co and the version from the stable branch in the buildbot.
Something must be weird on my system. Also the default font in my retroarch xmb menu is now a really large pixelated font. It used to be a nice-looking, smaller font. I can select the nicer font manually in the appearance options... no clue why the default is now this ugly one it seems like a bug.
Retroarch is strange, I hardly ever get to play it because every time I fire it up I experience all kinds of bugs and crashes, and then I just try to find workarounds. Like that trick of not loading a core, but only loading content. It seems like the basic functionality is not even stable. Or maybe the developers' definition of "stable" is just not what I think of when I read the word.