Designer file won't open in beta 1.7.0.10

[Dazmondo77]

Just fired up beta 1.7.0.10, most things open fine but I now need to do another page illustration in a children's book I'm working on but it won't open, it just bombs Designer, like a prat, I did the first 8 pages in 1.6 but all the extra knobs and whistles of 1.7 enticed me into opening it up and I got carried away and did another 2 pages and have since got up to page 19 while keeping the betas up to date, which has always worked great up till now - also tried to open a copy of the first 8 pages that were put together in 1.6 this also bombs designer 1.7 but still opens perfectly in 1.6  - I've also just tried to open the latest 19 page file in publisher beta which opens and coverts to spreads fine so thought I'd try 'edit in designer' which appeared to work but only opens the 1st page cover illustration - I'd attach the prob file but it is 5.28GB in size

[SIN616]

I just downloaded the Trail version and I have the same issue, i have tried using running as admin. and trouble shooting and nothing happened.