Just a quick check did you install the Adobe reader by yourself from the site or did it come preloaded. One way of doing it is by uninstalling the reader and reinstalling. there are time where installation can go awry for preloaded versions of software.
In the past i've with some users issues where by the reader kep giving an error. The unusally thing after i updated the java and added Flash and shockwave from the adobe site it appeared to rectified the issue.
I would say its worth a shot, what i've suggested. you never know.