What determines the Adobe reader version

Hello all,

I have a awesome document in pdf. Now the only "problem" is that it need a high version number of Adobe Reader. If i look at the properties of the document it says its PDF-version 1.4(Acrobat 5.x). But i can only open the document with a Adobe Reader version 8.0 or higher. If I open it with a lower version it says it can't open the document, that the document is damaged.

Is there any way I can see what item or whatever increased the version number? Or how i can get it lower again, so more people are able to open it.


Regards,
Ivar