Movie does not save

After agonizing minutes editing my video and waiting
patiently.
The video only saves up to 63% and then apparently hangs.
Ive trtied all different combinations(waiting up to 60
minutes at a time but it still stops saving at 63% with
the remaining time just increasing.

Is this a fatal flaw? Is therer a fix? Also earlier
versions of Windows Media Player cant read the mov
format. Any solutions?