Curious if anyone else has experienced this. Please note that this is not a one time thing. This has happened on multiple occasions totaling to about 10 or so times now. So, I'm just playing on phone using it like normal. Turn the screen off and lay it down. After it's been sleeping for 10 minutes or so, when I turn the screen on I am greeted with a message of something to the effect of "No SIM inserted. The mobile network will be unavailable until you insert your SIM." Funny thing is, I see the 3G icon in the status bar, but once I press ok to get past the message, my 3G vanishes. No internet access whatsoever. 3G will not come back unless I power down, manually remove the SIM for a couple of seconds, and re-insert the SIM. Clearly the SIM card is functional and when I remove it and re-insert it, it goes back to same place it was before. It's not like the SIM had slipped out or something. I had actually received a refurb when my data went out for over 24 hours with no reason and I sent back the refurb because my data came back. At this juncture, I'd only seen the "No SIM inserted" message once. Kind of wish I'd given that refurb at least a little bit of use before mailing it back.