You can make any change you want (change an ACL description, change the terminal length...) the bug will return.
The @sam25 post is concerning me most.
As I said yesterday, I've deleted the SNMP configuration and then I was able to parse and save the running. Just a few minutes later, the problem occured again for no identified reason.
Running the same OS than you.
An old bug seems to be back: http://blog.boreas.ro/2007/10/cisco-asa-issues-configuration-line-too.html
I've deleted all my SNMP configuration and I can now parse and save my running conf...