Hey, Dan!

Both of mine did something similar but only when it was under 20 degrees or so. Both had an issue of shifting up slooowwwly in the first mile or so. I decided to have the tranny fluid replaced (both had roughly 75 or 80K on them - it was nearly time anyways) & haven't had the problem since. I had the SRT out today at -8 this morning & it shifted smooth & easy.

Depending on how many miles your Xfire may have on it maybe it's time for a fluid change.