I'm sorry about the difficulty. We are using a
free forum software package, and I don't think either of us are clever enough to make substantive changes in function.
The popularity of the forum made the image verification necessary to deter spammer bots. We had one spammer bot send multiple porn photos to all users via private message, and they weren't very happy about that. We still have periodic human spammers sign up and post, but they do so slowly enough that the moderators can zap them before they cause much commotion.
I just looked at the register process and I agree that the letters are too small, and worse it's blue-on-blue. I had some luck with clicking "request another image" repeatedly until I could read the letters (which were the same between images).
When I tried to listen to the letters it seemed to play via Windows player, but when I clicked on the direct link Quicktime came up. It's in .wav format, so really any player should be able to play it. I'm not sure yet how it's choosing which player to use.
If we can figure out a way to make it better we'll give it a shot.