Well, it’s not really a betaversion (of the program) - it’s an updated version of the engine (scanner & unpackers). The engine is under continuous development… and we don’t release a betaversion each time I add or modify something in the unpackers (which would be every other day). Besides, this isn’t really something that can easily be tested (unless you have a HUGE collection of malicious files).

I don’t think there was anything special about this build… just that somebody decided that we might update the engine on VirusTotal, and the current engine (at that time) was used. The same may be true for Jotti, G-DATA AVK, …