Hi I know you have probably solved this problem by now but I had a similar issue
I had to open up the page in a seperate window and select the url for the page
then on another window access 'template' and 'edit html' on the blogger menu
when you see the html box, click on the screen and press 'CTRL and F'
this brings up a search bar... type into the search bar the title of the page which you have copied the URL for and press enter
this should find and highlight the correct place in the HTML for you
you will need to insert the URL into the html ... it is possible there will be '#' in place of where your page url should be or if you have changed your blog name then perhaps it will show the old page adress linked to the old blog name... just swap it for the correct URL of the page as it is currently
click to save changes and maybe that will work for you.
Hope this helps (you or someone else)