You have given us rather little information about what
your logic looks like. For instance
FreezeThaw
has various hooks to allow you to put logic in the freezing
and thawing process. Are you using those? If not, then
I would suggest giving
Storable a shot.
However I would wonder
whether your frozen string is getting long enough to not
fit in whatever database field it is going into. Check
whether that is plausible. (For instance report the
length of the string going in and coming out. If they
differ, you know what it is.)
If neither of those two naive guesses helps, you really
need to create a minimal test case. Do you have a reliable
interaction that does it? Can you script that interaction
on the command line? Once you get to that point, try to
start cutting out steps, and keep on going until you have
the shortest case you can that reproduces it. After you
get there, you are going to be in a much better position
to figure out what it is.