Have you tried turning the salary cap off, re-signing players (obviously, not anyone that would push you over the cap) and then turning it off after? I don't know if this works but it might. I'm re-building the raiders, and I was at 18m cash and 42m cap space, so I picked up 18m worth of players, and waited til the end of preseason to pick the rest up and they didn't seem to damage the $ number in the top corner.