Avast! has posted an update to their Antivirus programs that resolves this issue. It is dated November 11, 2013. Once you install the new version, obtained from**http://www.avast.com**, you must do the following to resolve the crash:
- Reboot your machine (the last step of removing Avast!)
- Click on the File Tab, and click Options.
- Click Trust Center and then Trust Center Settings.
- Click Trusted App Catalogs, and then click the Clear button.
After you do this and restart Excel, the crash should not occur.
If you have renamed your OSF.dll file, please go name it back to OSF.dll
After placing OSF.DLL in an new created folder the problem of Excel crashing when using the scroll wheel seemed to be fixed. Excel did not crahs anymore. I was too lazy to read all posts :-( and this post had 24 "found this helpfull" replies so why bother.
I know better now!
Then I had the same problem using the scrollbar on the right hand site Excel would crash as soon as I would touch it.
So I installed a new version of Avast, and followed the steps in Excel as written above.
For now everything seems to work fine, hope it stays that way because I find it very annoying and time consuming.
Thanks anyway for the posts it helped me a lot.