Congratulations. You're in the right place to help us make Auctioneer better by reporting bugs and problems. Before you make a new post, though, please read and follow the guidelines below.
Step 1 - Regardless of what it might say elsewhere on these forums, IRC, or the Internet: Do not add anything to JIRA unless you are asked to do so by a developer.
Step 2 - Always be sure you have the latest version before posting a bug report, particularly if you are using an preview, alpha, beta, or gamma version, since we tend to update these frequently. Please note that our site will often have a more recent version than what you might find on other AddOn sites (e.g. Curse, WowUI, etc.). Please be sure to grab the latest here, from our site, at the link I just listed.
Step 2a - Do you have both Auc Advanced and Auc Classic installed? If so, you must download and update both AA and AC whenever you update either one. Many, many people update only one, then post with issues. Please make sure to download and install both packages if you have both installed, even if you "only really use" one or the other. Alternately, disable and/or uninstall the one you are not using.
Step 3 - Always search the forums for existing threads dedicated to your bug before posting a new one. There is a search tab in the header of all forum pages: please use it.
Step 4 - When reporting your bug, please start by telling us: Auctioneer Classic or Auctioneer Advanced, or both? If you don't, it will be the first thing we ask, most likely.
Step 5 - Please tell us what you were doing (or trying to do) when the error occurred.
Step 6 - Please post the FULL error message, including addon list. If you don't, we will ask for it. [Cutting and pasting the data from your Swatter.lua file is better than nothing, but it's much harder to read - please try to grab the error from in-game, if possible.] If your problem isn't an error, per se, and you're running Auc Advanced, you can still help us out by running "/aadv about" and including the revision number that is output along with your report.
Step 7: If it is helpful, please take screenshots showing both the manifestation of any problems, and the options you have set which seem relevant to the problem. Screenshots can be uploaded to http://up.norganna.org/ . Do not forget to grab the resulting URL, copy it, and paste it into your post here on the forums or on IRC.