I have ST3 build 3047 and I observe same behavior on win7 x64 and ubuntu x64 machines.
I have a .cpp file and when I press ctrl+r to search a function I can’t find some of them. Unfortunately forum doesn’t allow to upload txt/cpp files, therefore here is a link to gist with source, so you can try by yourself: save gist as .cpp file, open it in ST3 and try to find function “processReceivedHeaders” by pressing ctrl+r. Only “processReceivedCookies” will be found. If you’ll try to find same function by using ctrl+f - it will success. Interesting that function fails to search only for some functions.