Data issues?

[blbx2]

So I got the Intrepid for Christmas and I was having issues with it connecting to the internet. If my phone was on and I hadn't used the internet on it for an hour (2 hours tops) then I couldn't connect to the internet via any method (IE, multimedia msg, email anything to do with data ) If I turned it off and turned it back on then I could use the internet for as long as I wanted (constant use) but the minute I sat it down unused for an hour (2 hours tops) then I had to restart it again. So after many calls to Sprint they sent me a new one in hopes that would help....well....the same crap is happening with this phone. Is there something that I (and the techs at Sprint) are missing in terms of internet use and maybe there being some kind of setting that I don't know about?