Cool down times in eyepieces...

Since getting my new Pentax XWs I believe I've started to notice a pattern.
They need cool down time much like my telescope does. If the scope is
cooled down enough, I can take my eyepieces warm out of the house outside
and put my ortho's in without a problem. They just work. However, when I
try this with my Pentax's I get that blurry feeling again, similar to mirror
cool down issues. If I wait about 10 or 20 minutes (depending on how big
the difference in temperature is) everything seems fine again. Have others
seen this? It's not a big deal as I now just put my eyepieces out to cool
with everything else. My scope seems to cool down in around a 1/2 hour and
that seems more than enough for the eyepieces too. Just curious.

Thanks,

Mike.