[SOLVED] C Code Parsing

I'm trying to write a scanner using Flex.
 
The problem is that one of my regex's works in the Visual Studio Find dialog, but not in Flex when tested on the same file!
 
By "not working" I mean that it doesn't find any matches.
 

\'((.)|(\\['"?\\abfnrtv])|(\\[0-7]{1,3})|(\\[Xx][0-9a-fA-F]+))\'

 
This regex is supposed to recognize any character literals, like 'a', '\t', '\012', or '\x01AF'.
 
Can anyone suggest why this regex is not finding any matches in Flex?
 
SOLVED: It turns out that I had other rules that were consuming the character literals earlier in the process.