Do Hard shell/Gel phone cases affect reception?

[kmf]

Just wondering if anyone has solid information regarding whether or not hard shell/gel/leather cases for our phones have any effect on the quality of the signal that the phone is able to receive and transmit?

 

[LaTuFu]

They do not have any effect on reception.

 

[ladybadger2007]

I have several cases gel, plastic, and plastic blingy. I have noticed that my phone seems to go slower when I have the case on then when it's off. Since the 2.2 update I have to turn my phone off a couple times a day, well yesterday I took the case off to restart it, and didn't put it back on and it seemed to do better, so I don't know . I'm seriously considering gettting a diffferent phone all together.