Just wanted to bump this.
I'm having the exact same problem, and I cannot figure it out. I've found it will go away if I wipe the Reader cache, but apparently it's not a fix-all because for one user it came back a week or so later and I'm told for another user as soon as they opened a different PDF it happened again. This is making me nuts trying to figure out, if anyone has any suggestions I'd greatly appreciate it!
I have exact the same problem with ACROBAT Reader 9.3.0 with a set of PDF documents which i got from our customer. The customer documents was build with ScanSoft PDF Create 4 (if the document properties are right). Collegues with the same ACROBAT version have no problems with the documents.
I have no idea what could be the reason - an solution at ADOBE?
I found after some digging around, that by wiping the cache the search began to work again.
By default I believe it's located at %userprofile%\Local Settings\Application Data\Adobe\Acrobat\9.0\Cache
No idea what causes the cache to get corrupt though. -shrug-
I have exactly the same problem. I use Acrobat Reader 9.4.0 and when I search for a word it takes me to other words or symbols that are not related to the word at all.
Nonetheless, when I perform a search with Adobe Standard 6.0 on the same document the search works OK.
Is adobe working to correct this huge problem?