This is very interesting to me as I was getting crashes when exiting games too, but was unable to get any help here which resulted in me having to quit using Recalbox sadly. I notice that in my .ogg collection on my install that I have four files with a higher sample rate than 44.1Hz. I will redo these and see if it gets the system stable again.
Thanks for posting your advice. I will post back if this works.
Pardon my b*mping of this topic but I think this may still be an issue for some users.
I have discovered the solution here. It turns out that I had 4 music tracks that were sampled at 48000Hz rather than 44100Hz, and this was causing the crashes. Remedying this has fixed the problem. Hope this comes in useful (and pops up in Google searches!). 
Well, just spent over an hour testing with the changes made to my background music, and yes it would seem that this fixes it! To say I am extremely pleased would be an understatement. I'm absolutely thrilled!
Thank you for posting the solution. I cannot wait to get back to Recalbox.
Sorry, it would need to be Linux based or at least compatible with WINE. I don't use Windows. Thank you for the suggestion though.
@bkg2k
Thanks for the great beta! One issue below:
[GPi Case] Raspberry Pi Zero W (not 2)
Mostly this is performing incredibly well. PCSX works now finally, and runs great. Many other issues also fixed, however FBA2X performed well on the last release but now does not work well at all. This particular emulator is needed for the low powered Pi Zero.
I place my usual compatible roms into the fba folder as before, but upon launching a game I get the screenshot added here. Display is moved onto it's side. Not only is the display skewed in this way, but no controls work. No buttons, no hotkeys, and also no audio either. Device must be hard powered off to exit. Note: These are PiFBA compatible CPS and NeoGeo roms, and should work fine with FBA2X. They worked well on previous releases and other OS's using PiFBA.
Previously on the last release, the display was squished down from 4:3 but otherwise worked well. See also screen grab below of last release. On beta, sadly broken.
Hope you can fix before release. The performance is otherwise quite astonishing for such a low power device.
@zephar42
Ah yes they changed this combo for newer releases of this case. Thanks for highlighting this as it can be useful for new users.
I mean, it might not be this that is causing the issue, but it's got to be worth a try.
@zing
Thanks for this. Sadly it didn't work. 
It looks like there's a setting in fba2x.cfg called maintain_aspect_ratio. This is always set to 1. I've tried to change this but it gets overridden each time I launch the emulator. Could you advise where I'd need to change this so there's no override? Many thanks for your help.
I should also add that I am referring only to CPS roms. On Neo Geo it runs fine. It's only on CPS that the display shows borders at the top and bottom, effectively squashing the display. Thanks.
Hi all. Just want to say Recalbox is amazing on the GPi! However, I have a problem with FBA2X. It is a brilliant emulator for this little low power device, but it's a little bit squished on the screen. Is there a way to fix this?
I should add I'm using the latest 7.2.2 Reloaded release for the Pi Zero/Pi 1 on the GPi Case. I Know there's the newer Pi Zero 2 but I haven't got that one. Thanks all.
@Zing
Thanks for replying!
The GPi case uses a Raspberry Pi Zero, which is nowhere near as powerful as a Pi 3. Hence why I was using PiFBA with a compatible romset. Mostly it's working OK but the Capcom stuff has the aspect ratio problem. I was hoping this was user fixable. I'll test FBN but I wouldn't expect much from it on a Pi Zero.
I do use Skraper on my desktop to get images and gamelists sets etc. I did this fresh for the Recalbox install. I did also try without any scraped info at all to see if that made any difference but it doesn't appear to affect it. On other devices the 2600 runs well, but on the GPi it runs very slowly. This is surprising as it's powerful enough to run this emulator, so it must b a config somewhere causing the issue.
Hi folks, hope you're all doing well.
Decided to try the latest Recalbox on my GPi case. Haven't used it in ages, but wow what a fantastic OS! Absolutely stunning and running very nicely. Brilliant that it works right out of the box with no real tweaking needed. Only occasional bugs with the UI, but that's not why I'm here.
While it largely runs really well I notice that for some reason Atari 2600 runs really poorly and is very slow. Is there anything that can be done about this? I had previously thought it was because my roms are zipped but unzipping them made no difference.
Also I have a PiFBA set from ages ago, and while most of them run well I can see the Capcom stuff runs in a squished aspect ratio. Again, is there anything I can do about that too?
Thanks for your help folks. Keep it rolling!
Sorry, it would need to be Linux based or at least compatible with WINE. I don't use Windows. Thank you for the suggestion though.
That's brilliant advice. Many thanks again for responding.