I also love how you immediately concur with the OP that it's a Verizon network issue, when you to seem to be describing completely different situations with completely different theories behind them.
Let me clarify, then. I agreed with the OP not
because of what happened to me at Dodger Stadium the other night (which, upon further research, does
appear to be due to generally crappy reception at the stadium) but because I went through this for months with the Bionic. (Hence the part of my post where I said "Been through this when I went through 2 Bionics before they sent me a RAZR.")
It was not a completely different situation. It was surprisingly similar to the OP's situation, except that, in addition to the new SIM card which didn't help, I also went through a factory reset which didn't help, a couple of network service tickets which didn't help, and a replacement Bionic which also ... didn't help. After a bunch of VZW techs who claimed to have no damn idea why my Bionic was dropping 4G (which, like the OP, I could get back by toggling airplane mode -- although sometimes it required turning the phone off and on as well as toggling airplane mode), I finally got a tech who admitted that it was a known problem (duh), and that ICS vastly improved (but did not completely solve) it. Which is why they sent me the RAZR -- as the Bionic's OTA ICS date kept getting pushed back.
My mistake in the post was in assuming (clearly incorrectly) that a signal in Dodger Stadium should be strong and solid. Bad example. I had similar problems last Thursday in a restaurant, when my RAZR dropped 4G (and went to nothing, rather than 3G). I've also had the same problem at home. So, no, I didn't concur with the OP based on a different situation. I concurred with the OP because the post sounded suspiciously like the data dropping hell I've been living through since June.
I appreciate you filling me in on the situation about stadiums. I don't appreciate the gratuitous snark.