hyperlinks with Acrobat Reader 9

Hi folks,

I know it's not pure html and web design,
but maybe you can reffer to...

I have some ebooks that the hyperlinks worked very well
with acrobat reader 8 and previous versions,

with ver 9 they not working,
When you point with the mouse it says something like:
URI:<the url name>
And you cannot click on the link,

Why it happen?

Thanks a Lot,