Virus changing patches on it's own??

[OSS_Synth]

I have just started using a Ti Snow. I play synth in a band so it's almost solely used for live performance. Tonight was my first band practise with it and it is changing patches randomly in the middle of playing without me touching anything on the virus itself. For example I started playing on RAM bank 1 1-1 string sound I made, then skipped to 2-4 on the same bank resulting in my ambient atmospheric strings turning into a high pitched pad sound.

I went into the config menu to see if I could see anything that might cause it to do this, there was a change program option which I disabled and no problems after that.

Just asking really if it was a coincidence or if what I did was correct. We have a gig on Friday, a pretty important one to us and I need to know that it's not going to change mid song and make me look very stupid. Is there anything on the virus which should make it behave this way or is it a faulty unit possibly? Any help much appreciated.