Russ,
Vision Microsystems was purchased by JPI instruments. They still manufacture the VM1000C, but with a number of changes/improvements. They also changed to all JPI sensors. I had an original (never run) VM1000C and heard from others that JPI was not supporting the old version, but would provide a free exchange for the updated one. My was installed, so I removed it, sent it in and was provided a replacement free of charge

. Can't beat that for service. It has functioned trouble free for my 15 mos in the air. I'd try and contact them to see what they can do. When I talked with them about keeping the unit or exchanging it, they said that some issues occasionally came up with the old units, but they may be just fine left installed. I took the safe but cumbersome route and removed and replaced the unit.