Do you guys think that having a 15 minute nap after lifting weights would have an adverse effect on my cutting goal? After every weights session I always feel sleepy (not tired) and for the last couple of days I have been drinking my PWO shake and then having a nap for 15mins. When I wake up I feel really refreshed.
My eating, calories and sleep (get 9.5hrs daily) are all up to scratch so I dont think its an energy problem.

No, rest is good. Rest is when you rebuild muscle. If you want, have your PWO and sleep for an hour or two. Get up and eat a meal after that. :P Make sure you are getting enough sleep at night too. Eight hours!

I do it too.

Lift heavy - PWO meal and Shower - Sleep for a while (few hours if I have the time), meal, back to normal. that's ontop of the 8+ hours I get a night. Although sometimes because of my job I can only get about 5 hours sleep, so I'll sleep longer after workout.

The thing i would worry about is that napping would slow the heartrate and reduce blood flow and digestion. I think this could be a little counter productive straight after PWO. I am just guessing though.