If you edit a post that contains a link and place a new link where an old one used to be (as in, the same piece of text changing from a link to one url to another), the end result when you save it is no link. This is using the button, the BB tags, as the BB tags have their own linking problems.
Readers: If you need to do this, delete the original text completely and re-enter it until Chucky's able to fix the button.
Testing below:
Jz is a sucka (http://www.fight-evil.com)
Can you recreate the problem? I'm having trouble creating the problem for myself using the information you have given. It all seems fine to me. Are you sure you didn't just accidently leave out a part of the code? It could coincidentally been linked to the other problem with the 'spam links' which is now fixed.
Try to recreate the problem and let me know how you go, if it is fine let me know and I'll mark this as fixed.
Here's where the link should be.
Modified...
Done. No code that I can see when I go in a third time to do anything with though.
You can't manually add the url tags in? I think if you're editing, it's not a big deal to do it manually instead of using the button but if it's happening on the initial attempt to link, then it would be a problem.
Now that the BB tags are working, it's if anything a minor inconvenience.
So I'm fine to close this thread, then?
Yes / no? Is there an actual problem? [*uhoh*]
It's a problem in that it happens, but it's easy to fix on a post by post basis, so if it's not something you can permanently fix easily it might be better to close the case, yeah.