There has been an update to Shockwave though I have avoided updating mine. It seems that everytime there is an update, it often causes problems. Perhaps, if your computer is set to automatically update programs, that might be the cause of your problems.
Also, if your shockwave is running a much older version (for example - more than one version older than is current) when the new update comes out very often VMK will not run on that older version anymore.
At this point, try checking to see what version of Shockwave you are running. I am running 10.2.0.22 and it is running fine. The newest version is 10.2.0.23. Also check that if you are running automatic updates that you dont have too copies of Shockwave (often if you have two different browsers loaded on your computer this happens). This can cause problems too. In any event, try uninstalling Shockwave and then reinstalling it.
Dont use the uninstall program from your computer. Use the one found on the Adobe website. It will safely remove all instances of Shockwave from your computer. There is one for Mac platforms and one for PC's
Save the uninstall program on the Adobe website to your desktop first.
Then open the folder and select run. Once the program has finished the uninstall, go back to the Adobe Shockwave site and reinstall the program.
This may solve your problem.