I am also experiencing the same issue. I know prior to 7.5 mobile was working fine.
We use Blackberry and iPhones for all of our users and all get the same error as described.
We applied 7.5.1 beta5 today and still get the same issue. java.io.EOFException.
Any other suggestions to try?
The devices have “Accept Cookies” turned on as well as “run java script” as on.