Almost a year ago, I purchased a script to create search engine friendly urls and meta tags for one of my forums. One of its features was to create unique meta descriptions based on the first X words of a thread's first post.
A few months later, I upgraded the forum software.
Since my memory sucks, I have to make some assumptions here. I believe when I first applied the se-friendly script, I checked that everything worked as it should. I assume that when I upgraded the forum software, something went awry, and I didn't re-check that all the se-friendly options were still working correctly.
I just noticed (yes, JUST) that the meta descriptions were mangled. Instead of using the first X words of the first post as the description, it was only using the FIRST CHARACTER. So, the description was "A" or "b", etc. Ack!
I would say I've learned my lesson to continually pay attention to the small details, and not to put all my trust in a script's abilities, but I know that in the future, my memory will fail me yet again, and I'll forget to check everything. With any luck, though, I won't make THAT mistake again, and hopefully you won't either.