Debugging
The X Windows System is a critical component in the Ubuntu operating system. X is not without its bugs, but fortunately debugging X issues is not rocket science.
The vast majority of Ubuntu X issues fall into one of several distinct categories, and based on the way they manifest, there are several different tactics that can be employed in a nearly paint-by-numbers fashion to isolate them.
Contents
X/Reporting - How to create good X bug reports
X/Glossary - Explanations for commonly seen terms and error messages
X/Backtracing - How to collect a backtrace for an X crash
X/Triaging - How to ensure new X bug reports have enough info to troubleshoot
X/Troubleshooting - How to analyze X bugs to make them solvable
X/Bisecting - Using bisection techniques to solve regressions or backport fixes
X/Quirks - Fixes for some common hardware-specific issues
X/Upstreaming - Forwarding X bugs upstream
Other Resources
Video Resources at help.ubuntu.com
XorgOnTheEdge - for bleeding edge packages
BinaryDriverHowto - for installing fglrx or nvidia