This worked great for me as well!
I am currently on Studio 3 and running Snow Leopard. This is how I got it to work
I first downloaded the 2 Prokit files as reccomended. links below.
ProKit 5.1 (You will first need to install 5.0 before running this) http://support.apple.com/kb/DL1008
I then went to Macintosh HD/System/Library/PrivateFrameworks I noticed that there were two ProKit.framework folders in this location. they were ProKit.framework and ProKit(SnowLeopard).framework The only one I deleted was the ProKit.framework.
Note: if you are having trouble completely emptying your trash download this and it will make sure to empty everything in your trash. http://www.macupdate.com/app/mac/8214/trash-it!
I then copied the previouly downloaded ProRuntime.dmg to a thumb drive so I could extract the info. Once the package was done extracting it gave me a folder on my thumb drive called system once you get to the bottom of the sysem folder you will see two folders one called BrowserKit.framework and the other ProKit.framework. From here I copied only the ProKit.framework folder over to the Macintosh HD/System/Library/PrivateFrameworks Folder. Once this was moved I ran the ProKitUpdate5.1.dmg from my desktop and all was rignt in the world.
Hope this helped!
I had the same problems after upgrading to snow leopard, and this worked. DVD Studio Pro 4 once again runs without crashing.
However, now Aperture will not start because of a problem. If I reinstall the latest Aperture 3.2.3 update, will it undo everything I just did with reverting the ProKir.Framework?