From my home connection the domain ip has changed, but from my server it still points to the old. I tried ipconfig /flushdns but it doesn't work. Other idea?
It depends on how long ago the IP address was changed. Sometimes you have to wait up to 48 hours for DNS changed to propagate. Try again in 48 hours and let me know. Also have you tried rebooting the PC & Router?
You are really waiting for your ISP's DNS to update, rebooting your system will have no effect if the DNS server still has the incorrect IP. To be honest a "few days" is pretty slow for DNS propogration these days, there may be a configuration problem somewhere.
On both of the box's run the command nslookup ddomainame in command prompt, use some online tools like http://www.squish.net/dnscheck/ to see if you are getting the same ip resolved.
Try changing your DNS server to some public one and see if it works, for example you can use 126.96.36.199 which is googles public DNS.
Also make sure that you dont have that domain statically set in a hosts file (nslookup will ignore the hosts file.