I have used Pinnacle since v7 and have to say 9+ is its most stable version it does have a recent update patch but in general does not live well with many other programs.
I generally create multi boot systems and put video editing programs on fairly clean windows installations so I Very rarely get the problems you experience. I hate to have to agree with melliot1963.Pinnacles "bad" name is unfortunately deserved ( even though i seem lucky with it . Its hit or miss behaviour is to be polite annoying. Keep your Pinnacle by all means but perhaps Adobe Premiere Elements ( a tad less user friendly to use but oh so stable and very affordable )is one way to go. It also authors dvds
http://www.adobe.co.uk/products/tryadobe/main.html
Adobe has such a following that if you have any problems with it somebody has probably been there before you and there is a fix
On a more general note ,Dual layer dvds are great for data storage and theoretically for large amounts of video but at present the inconsistencies in results for video are ( to me) somewhat worrisome and perhaps 2 single layer discs may be an easy escape route for you
good luck