I thought I answered this last night. Pinnacle sees this section of the video as corrupt or unreadable. If you say you've checked the file and it's ok with other editors then I can only suggest you use one of these other editors, as Pinnacle is having trouble with this particular clip or transition or media.
There's no way it should take more than a couple of mins to load a project and that's on a slow machine. It can sometimes take a while to split out the sections that Pinnacle likes to do but when you first load a clip but it would have to be a long piece for it to take a long time to do this.
I'm not sure what else to advise.