I just picked our NAD C272 power amp from my dealer who had sent it away to get a small glitch repaired in the variable/fixed input switch before the warranty expires. I ask them also to check if the amp had had the cap upgrade. It hadn't so they did this as well as replacing the power supply and fitted the mod wires to the pcb.
Now I can sell it happy in the knowledge it won't go up in smoke for the new owner. I have always kept it on a well ventillated rack, but the warning is on the NAD website for C375 and C272 owners for those who may stumble upon it. Why they didn't instruct dealers to send notices to customers is a bit beyond me. Anyway, it really may pay to make sure your unit has had the cap ugrade done for your peace of mind.
Good post M.R. Thankfully mine has the new caps. My dealer was telling me a story, that a C272 customer had a first gen cap blow. He sent it back to NAD recently to get it fixed and they replaced the cap with ANOTHER first gen cap. My dealer was so outraged that they did this, he gave the customer a full refund on the C272 towards a new Bryston. So I agree, make sure you get the upgrade.
Dave, Nick answered your question, but it still depends on how long your units were at either the distributors or the dealers before they were sold. My distributor told me mine was most likely okay when I enquired about this quite a while ago. I wonder if an email to NAD asking for serial numbers to determine the units prior to the upgrades would help?