I'm just curious, have you solved this issue yet? I haven't downloaded the user manual, but if you have there may be ways around it. If Vortex cannot provide you with the older firmware which they should, there may be other places to download this. Just be cautious these can be riddled with spyware and what have you, so scan before opening, especially executable files.
If you follow the manual, look at the dipswitches, there may be ways to swap Caps with Ctrl or turn Caps into FN. This way if you press it by itself it will not effect future keypresses. This hasn't seemed to pique a whole lot of interest, but please if you get a chance update; I am curious. Thanks.
Also, as a rule, look at the fixes the firmware upgrade introduces. If none affect you then it may be best to leave it.