Mail & WIFI Issues

I am having difficulties receiving mail when using my iPad2 with a WIFI connection. It appears that I can send mail but does not receive mail when I hit the refresh button. I have tried 3 different WIFI locations (Starbucks, public library and a neighbor's network), I can receive mail if I turn on my cellular plan with AT&T. Also, I have checked the mail settings and fetch is set to push and I have also reset the network settings in the General Settings. Any suggestions or ideas would be greatly appreciated.

Can you connect to the Internet using Safari on WiFi? It's a strange problem that you have because, normally, it's the sending of email from a WiFi location that proves troublesome. Clearly your email settings are correct because you can send and receive email using 3G and you say you can send email on WiFi. So it's a bit of a puzzle, but just wondered if there was any problem using WiFi and Safari.

Tim

no problems with safari, facebook app, nbc tv app, etc... really strange... any other suggestions.