Acrobat reader pop up annoyance

[ixy]

Hello,

Every time I try and open a PDF file with features newer than what my Acrobat 6 supports, the following window pops-up. I have tried to tick "Do not show this message again" but it keeps coming back. i reckon I might not have enough rights to banish it but i am a domain admin which is somewhat odd. any help will be rewared by muffins

Cheers