I am running Acrobat Reader 7.0.5 (free download version).
I don't know why, but any searches of your PDF manual never matches any text in the document. I have looked at Acrobat's options, but don't see any way to resolve this.
I suspect that either you have done something really odd with the character set for the document or else the entire document is completely bit mapped images as opposed to text.
Assuming that this isn't a problem specific to my Acrobat installation, you might want to fix this especially if you produce a more extensive manual in the future. Being able to search is a nice feature for digital documents.
Thanks.