Not sure if it's related, but I can't get the x86 v5.19 version to boot on my 64-bit machine at all. I had intermittent problems with earlier versions too, but booting first on a 32-bit machine fixed the problem.
I posted a thread on this here:
The 64-bit works fine for me, though. I presume that's what you're using?
As for the ROMs, are you using a MAME version that corresponds to the ROM versions you're using? I used a Windows program called "Rom Center" to audit the ROMs and fix them to ensure compatibility with the MAME version in Batocera.