Heh. I had the same problem. In testing, I searched for \\% and it found nodes containing \%. I eventually tracked this down to a bug in MySQL. To match \\ in a string in MySQL you have to say LIKE '%\\\\\\\\%' and I was only saying LIKE '%\\\\%'. Weird.
Anyway, after I put the patch in to work around it I searched for \\% again and the first match I clicked on was a node that contained \% but no \\%. I scratched my head for a while on that until I decided to "view source" and search through that. (:
(but my friends call me "Tye")