It seems that the site has an active security system.
See : http://www.avgthreatlabs.com/sitereports/domain/seatsandsofas.nl/
Now CLEAN according to Sucuri : http://sitecheck.sucuri.net/results/seatsandsofas.nl
And also CLEAN acc. "Unmask parasites" : http://www.unmaskparasites.com/security-report/
Edited : Visited the site itself and checked it : Very good site, PP, disclaimer and ToS !
The site is under active control of the webmaster(s).