On the other hand, I only use a Snark and I have never had that problem. Nor has my guitar muse who I introduced to Snark and who starting using them with no noticed problems. Still, JeffS65's explanation is interesting.
My first thought was that the string itself that was the issue and then thought it was a tuning peg problem EDIT or the winding of the string on the peg. END EDIT
There's an old guitar quote, who said it first is lost in my memory; "We spend half our time tuning our instruments, the other half playing out of tune."
Good luck, have fun.
"It takes a lot of devotion and work, or maybe I should say play, because if you love it, that's what it amounts to. I haven't found any shortcuts, and I've been looking for a long time."
-- Chet Atkins