There has been a major bug when opening pdf files from Internet Explorer 7. The latest update of Acrobat PDF reader B8 has fixed this issue. I suggest to download and install the new update for reading these pdf fiels and and any other from IE7.
The download link is found here:
http://www.adobe.com/products/acrobat/readstep2.html
Crash of pdf reader from IE7 - fixed
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