Well, the issue you report is not listed in the Known Buglist for Filemaker GO maintained here in the Report an Issue section. We'll have to see if this one can be confirmed by FileMaker Inc. There are possible explanations for what you report that would need to be ruled out.
I agree that the the search engine has many problems.
Thank you for your post.
Unfortunately, I am unable to replicate the problem with FileMaker Go (iPad an iPod touch) with files hosted on FileMaker Server 10, FileMaker Server 11 and FileMaker Pro 11. If you have a specific file that I can duplicate the problem, please send it in. Check your Inbox at the top of this page for instructions where to send the file.