If you find a bug, or would like to request a new feature, you can either e-mail the mailing list, or enter a report into the bug tracker. The bug tracker contains a list of all known bugs open on the last release (often these are fixed in the git version for the next release).
Please make sure to read the documentation before reporting any problems.
It's generally best to discuss feature requests or patches you have on the mailing list before using the bug tracker.
Bottlenecks occur in surprising places, so don't try to second guess and put in a speed hack until you've proven that's where the bottleneck is.- Rob Pike