I've got a couple of 195As, both on my todo list. I bought the first one for fun, but it had slowly wandering readings (i.e. a few 10s of counts over the course of a day). As a TEA sufferer, I naturally bought another one to compare it to... and found that it wandered even worse
. Despite this, I still dont think that this is normal behaviour, just that they are suffering from the same affliction. To be fair, the casing of the second one had been smashed to bit so it wasn't in best of condition.
Anyway, the point of this waffling is that the second one arrived with the uncal error, and a quick subsitution showed that the xicor X2212D NVRAM was at fault. A "new" chip from eBay solved the uncal problem (but not the wandering readings).
BTW, at least on my units, the 5V regulator runs really hot. I'd be interested to know if your 195 is the same.