There is something weird going on with your server -
First of all, I'm trying to access your gallery standalone, but it won't load the main menu. Do you know why?
http://www.spiegelschlag.de/beta/galery/
Regarding the @ symbol - I had to use shift+@ on your site, while normal for my keyboard is Alt Gr+@. There is something weird going on with language/charaters on your site, as it is decoding all my keyboard input into another language or another language keyboard. The layout is not for my keyboard. I am not sure if it is the site, or if it is the server that is doing this. I would at least send a request to the server admin.
Regarding the mouse wheel, it seems to be something with your server also. As you can see from our demo site, the scrollbar works on all other sites:
Imagevue Soda Demo
I even checked by another method. Go to your "contact" page, and fill in lots of text in the message field so it overflows. Then try to scroll with the mouse - It has no effect on your site, as if the mousewheel has been disabled for input. The scrollbar here doesn't move anyway, but by default the text should scroll.
This is very weird, but all I can say is that it's not Imagevue's doing. It seems to be some kind of server attribute.