shrinking and enlarging layers

Hey everybody,
First of all I would like to say thanks for providing such a helpful site! Although I'm brand new to this particular forum, it seems to me that many people can really benefit from these unique networking opportunities.

Now on to my problem... I've been using Photoshop for almost a decade now, and I've come across a "first time" issue. I'll apologize in advance if this seems like a newb question, but I've never come across this until now. OK, so in my experience, I've been always been able to any layer, make it smaller, commit to the change, and then later go back to it's original size without losing any quality. Well ever since I upgraded to CS5 it loses quality when I bring it back to the original size? I fully understand that images will get pixelated when enlarging them from their original state, but why does it seem to be resetting and forgetting the data after it's been shrunk? Any idea what options may have changed from CS3/4 to 5? I've played with the "resample" drop box in image size menu, but that didn't help at all. I'm sure it's just some simple little check box that I'm missing, but I'm stumped. Any advice would be greatly appreciated. THANX AGAIN!

CRAWL

Sorry, it omitted a word in the sentence "OK, so in my experience, I've been always been able to COMMAND-T any layer, make it smaller, commit to the change, and then later go back to it's original size without losing any quality."

Try converting before resizing to smart object, that should help