Sanbox - Virtualization

Interesting dilemma, need opinions from our members.
I have been running Firefox v 9.0.1 in the sandbox/virtualization which everything ran well. Than all of a sudden ran into problems.
1.) My web email would not accept my password stating invalid.
2.) Passwords which were stored in the firebox security section would disappear.
These are 2 of the major issues at this point.
To add on I would from time to time delete the contents of the sandbox.
Now when this issue started I took Firefox out of the sandbox and everything is back to normal??

It appears that it is not advisable to run the browner continually in the sandbox as application are affected. What can anyone add on this problem??
Thanks in advance.