2004 Top and Frame - I've run into a glitch
 

I've run into a problem installing a 2004 top and frame on my 2000 Boxster. As you can see in this picture, when the top is far enough forward to engage the windshield header, I cannot slide the rear of the frame down into the car. Something seems to be catching it.

http://forums.pelicanparts.com/uploa...1358703243.jpg


Does anyone have suggestions for helping this fit in? I don't want to put too much pressure on anything. The old top came out without much trouble. Thanks in advance. I've been using the instructions on Mike Focke's web site,
https://sites.google.com/site/mikefocke2/removingthetopandframe and the author did not indicate any problems of this nature.