Unfortunately, I too seem to be having issues with my Ergo Pro. In my case, it's the space bar that's the problem: it's suddenly started to send a steady stream of blank spaces even when the key is not depressed, as if the switch had become stuck in the "down" position. Needless to say, it's quite unusable in this state, which is downright vexing. Niggles aside (and there were some, *cough* numlock key *cough*), it remains the closest thing to an M15 that's still being manufactured, and it's sad to see it crippled by reliability issues.
I have contacted Matias support, but I fear I'm screwed: the board is out of warranty by a few months, and seeing as I'm based in Spain, postage to Canada and back may cost a small fortune — on top of the cost of repairs and the potential circus of having to go through customs again, which proved very expensive and infuriating last time.
Waiting on the response from Matias support now... Fingers crossed!