The canakit and soarkfun probes has a black coating and mine is going on for 4 months now....
Interesting, so they dipped it in something... Yours is a 1wire, ds18b20? The last I checked your thread you were using an analog sensor?
*** edit:
https://www.sparkfun.com/products/11050
They put a casing on it... six or so months ago, this was a 'stainless' end... Interesting...