I've a Problem with the captcha. I tried it in IE10 and Firefox with the same result.

I call my page the first time, all things ar ok. I saw an empty contact form with captcha.
Then I make a test and fill out the fields for messsage, subscripter an so on (all what I've defined). I defind the mathcaptcha. It shows 7+1 and I put the result 8 in the field and press submit. After that I get an error: Ungültiges Feld: Sicherheitscode. (invalid field: saftycode). The captcha Image is gone and in the field safetycode stands an alphanumeric sign "b" and not an number. The same issue get I with the alphanumeric mode.
The captcha was seen some times later. The I can try this game oncemore. I think a saw the captcha later, because the sessiontime was out.

I'm using Linux and my Page was not online, only on my homeserver for testing.