Please reinstall the flash. I faced the same or goto help and update to the latest one.
Can you please answer few of the question below .
Are you working on a Network ? and if Yes What kind of network was involved?
What platform? How was the network file sharing set up?
Did Flash file Duplicate symbols etc in the middle of the file saving?
Yes I am working on a network. Not sure what kind - can you explain?
Platform is Windows 7 - latest version of CS5.
The duplicate symbols only appear when you close the file and reopen it.
Network like local area network (LAN) or networked drives/folders . Here is the link which will give you more information on this
Can you still reproduce this issue consistently? If yes, please email your sample .fla file to us at FlashAuthBetaBugs@adobe.com.
Please also include the exact steps necessary to reproduce the problem
Our email filter does not allow .zip files; therefore, make sure to change your attachment extension to .zzz if you are sending in .zip format.
Yes I am working over a network. I never realised it was a problem - we have worked on hundreds of projects before using the same setup!
The .fla is 17MB - is that going to be OK to email?