3G connection sometimes won't reconnect!

[androide]

I've been having different scenarios in different areas where I know for sure there is 3G signal where my phone won't reconnect or connect at all.
Let's say I'm a hotel at the same spot and try to open the browser and it won't connect,; so, I check my 3g connection settings and it says it is connecting but nothing happens. I try everything and only a reboot will work. Sometimes when I get off a 3G signal (due to a concrete wall,etc.) but then come back to a known good 3G signal area, my phone won't reconnect no matter what unless I reboot it!
These been going on lately, intermittently.
Any ideas?!

 

[bigk]

Alot of the time just disabling and re-enabling the mobile data does the trick. I've had it once or twice where the mobile data is greyed out.

As you know the last known thing is to just restart the phone.