Do save frequently, do back up...Do save the preset you've spend a long time building...yes yes, but...'
But if we are expected to make a backup copy and/or "save as" under different name before every freeze or similar function, it can get a little ridicilous IMO. There has also been so many threads about the uncomfortable sides of autosave, ( many of the veterans have said they don't wanna use it) that teacherlike stiff index fingers are not needed considering that either.
I don't find it unreasonable to expect some reliability of the software. I would be angry as well, and even if I'd be more careful next time, I'd find it a little unreasonable to be treated as if I had done something wrong. We all learn our lessons about not trusting the software, but the frustration is just and....frustrating, nevertheless.
Many comments above offer plain "saving" as the solution, allthough lack of saving is not the problem here, but that he had not saved under different name prior to freezing, or that he had not saved the preset.
In this particular case, I'm curious whether freezing the synth or the track makes any difference?? Also OP doesn't tell if the synth is in the synth rack or in the FX bin. It would also good to know what softsynth it is. There are dozens and dozens of VSTs that are known to have all kinds of imperfections. Blaming Cakewalk without giving closer info is, after all, a little hasty.