My MDC box went on the first voyage this year as well, thanks to my TTOCD I figured that was the problem right away. took the speedo lines off the box and water started leaking everywhere. For future reference, the box is dead easy to replace yourself if it ever happens again, for the cost of the box, I may have asked them to cover the cost of the box and I'd pay the labour!
When I talked to my MC dealer they said the pitot lines are supposed to be self draining so they don't blow them out at winterization. Regardless, I am adding it to my list for next year. I think I may take the first voyage every year with the lines not attached to the MDC box for a few minutes as well!