I found that there are 2 separate issues:
1) Viigo freezing on launch
2) unable to scroll articles
Solutions:
1) delete viigo from BB. Download Viigo OTA from getviigo.com and install. It will work even though it shows the same version number as before. Do not use the App world version.
2) simply select 'page view' from within the article in the menu and scrolling will work. This is a workaround but it is very simple and quick. I was doing this for quite a while then suddenly scrolling began to work on my Bold 9000 (5.0.0.314) but pictures stopped appearing. Now on the 9700 (5.0.0.344) everything works perfect with viigo