I've been using 'A hand Full of Audiosurf Addons' for quite a bit.
At one moment I came across the options button, where I tried 'Check for updates now' Seeing there were updates available, I went ahead and I thought I did everything correctly. Up to the moment where you were asked to manually delete the updater executables.
Why am I telling you this? Because right after that I ran YAAP, the icon did show up on my task bar. But the actual window does not. I couldn't help but make a connection between this and the (perhaps failed) update.
It might be possible that the window does indeed show up, but that it's invisible, as in placed out of my screen space. (Unsure how to exactly explain.) If this would be the case. How can I get that window back in my field of vision?
If this is not the case, I'd appreciate some suggestions =)