Yes all caps is what you want to see. although from time to time you might see 1X, this is okay as well, this means you are not seeing high speed data, but data is working.
You stated that you flip between the two. Redo your registration.
If you are using 4.5.0.138 or 4.5.0.160, I've noticed there was quite a bit more fluctuation between 1XEV, 1X, 1xev, and 1x. But I thought it was mostly with Verizon users.
I live in a weak EVDO signal area, so I see quite a bit of dropping down to 1X. It really sucks on my battery life too.