I just installed Adobe Reader 9.4.7 on my Ubuntu 12.04 Beta system, and hit this bug. I had no idea why filename completion was suddenly broken until I did some searching and turned up https://bugs.launchpad.net/ubuntu/+source/acroread/+bug/769866/comments/7 . So, the bug is still there, over a year later.
Adobe, please fix this, or else get rid of acroread.sh . It's much worse breaking filename completion than whatever bit of extra functionality it might be providing to acroread users (most users won't run it from the command line in any case).
Thank you for reporting the issue , we are now tracking this internally through a bug and hope to fix this in future updates. However , till then you may use the workaround #10 as suggested in the link https://bugs.launchpad.net/ubuntu/source/acroread/bug/769866/comments/10 . This looks specific to 11.04 and now to 12.04 Beta as well.