How do you have your subs wired?, I remember you saying to have 4 ohm Dual voice coils. Your amp might have gone into protect mode. If I were you id check the leads to make sure you have all the +'s and -'s properly set , even if it means taking the subs out. Check the manual to see if there is any indication it went into protect mode (like a light went from green to red). I'm really curious as to how you have those 4 ohm DVC subs wired to that amp. I'ts not a 1 ohm stable mono-block, and in that sense it's not a true mono-block amp, it just means you can wire it to one 1 ohm. I doubt the channels are separate on that amp.
If you take the subs out take a picture of how they are wired please.