First of all, you can flat out delete the StrataFrameInternal database....it is not longer used. This may be part of your problem. Also, StrataFrame 1.5 is stable as we have been using it for a good while ourselves. If there is something in the install that needs to be fixed then we will get it taken care of and get you going...but as for the release itself, it is very stable. So what errors are you geting?
Oh...to load the new build, just uninstall the existing 1.5 and then load the new 1.5 update. To clear out any old DLL references, it might be a good diea to clean your solutions: