Nokia issued a software update for the Lumia 900 Windows Phone to fix a data connectivity bug.
The bug caused Lumia 900 phones to drop their network data connections due to a memory management issue.
Thankfully the issue was software-based rather than lying in the phone's fundamentals, so a quick update through the Zune store will solve the problem.
Advice: ask for help or take the phone back
To Nokia's credit...
Nokia and Microsoft pinned a lot of their hopes on the Lumia 900, which runs Windows Phone 7.5 and comes with a large 4.3-inch AMOLED screen, to make a splash with users who may be interested in alternatives to iOS and Android enabled handsets.
You can check out our early thoughts with our Hands-On: Nokia Lumia 900 review