I changed my nameservers to new host. logged in to vbulletin control panel, and suddenly shows account suspended? while my new host confirms account is active. Old host did suspend me why am i juggling between 2 hosts nameservers at the same time!!?
Maybe nameserver propagation has not been completed yet. On the other hand, if your old hosting account had was associated to a dedicated IP, problem may come from it. I don't know how or why, but happened to me at Proaxx, kind of server misconfiguration.
This article helped me. http://www.geekshout.com/software/windows/how-to-not-wait-for-dns-propagation/