This has been my experience. The 2-3 times I have not been able to check in on line for domestic flights I have been given the SSSS BP at the airport.

but, as some compare the SSSS treatment to a concentration camp enlistment, I actually found it to be beneficial. I was able to get through the security line much quicker than the "non-suspects"...

I'm not advocating that we should all surrender to the "extra feel" line, but at the moment it's not as bad as it sounds.

Unfortunately that won't help you with the upgrade......

Good luck!