I'm having the same problem. Have you managed to figure out what's wrong with it?
Is the system date on your computer correct?
The system time is correct.
the forms seems to work when we use IE to open the form instead of Acrobat Reader program itself.
We have been using that "solution" for now.
I haven't tested if Reader X solves this problem.
My organization is having this issue as well. At first we thought it has something to do with Windows 7, but none of our engineers were able to troubleshoot and determine the root cause. I am curious to see what the response will be now that other organzations have reported a similiar issue.