@Goodwin @roytam1 I'm not a professional, I just compile Mozilla based browsers for my personal use and hope for the best. For instance, I'm trying to compile Firefox 13+ with Windows 2000 compatibility. One thing that sometimes (but not always) causes runtime execution failure is clicking on tools -> options -> applications which can cause an error in MSVCR71.DLL. Also, after reverting the commit that broke Windows 2000 compatibility, I had a minor problem that is caused by opening a new tab, and the message displayed on the new tab page was relating to an invalid address. That annoyance was caused by the commit for Mozilla bug 728429, which mandated ASLR on Windows. In order to find that, I had to cherry-pick a range of commits between the one that broke Windows 2000 compatibility, and the one mandating ASLR, then compile the source code a few times to narrow down my search. The point is, if a problem does not exist in one of roytam1's browser builds, then exists on a later browser version, the right thing to do is find out what the last good version, and the first bad version is, then it would be easier to find when the problem started, and what commit caused it. Also, it is possible a bug might not affect everybody.