Hello Jens

It may be possible that your ISP is being blocked due to some type of percieved illegal activity from someone else in your IP range.

Another but maybe slim possibility is that you may be running some type of back door trojan you're not aware of that the site detects, so they may be blocking you.

It also may just be accidental that they are blocking you.

Here is some contact info for you.

code:
Contact Us
  Sales & General Inquiries:  
    Electronic mail info@scriptlogic.com  
    Phone (US & Canada) +1.866.727.4785 (toll free) 
    Phone (International) +1.954.861.2300 
    Fax +1.954.861.2399  
     
Technical Support:   
   On-line support website scriptlogic.com/support 
    Phone +1.954.861.2350 
   Worldwide partners scriptlogic.com 

 Corporate Headquarters (USA):
   3195 North Powerline Road
   Pompano Beach, Florida  33069