Just in case, you do not know this tool yet…
http://zrusin.blogspot.com/2011/04/apitrace.html
Here you can download GL debugger similar to gDEBugger, but working even with GL3 (should work with everything up to GL4.1, but I have not tried it). It works fine for me in linux and should run in windows too. Very useful tool IMHO. Thanks to author.