Leosghost - 6:22 pm on Nov 6, 2011 (gmt 0)
Do you by any chance have a "back up account" with your ISP for if your cable goes down? ..the kind of thing that you can connect to with just an old style modem?
That would ( if it was using the same IP as your router ) allow you to really confirm that it was the server end ..
Failing that , best I can suggest is that you persuade your hoster to give you another IP at their end for your reseller account..but keep the nameserver settings that allocate incoming requests to your customers and your accounts..if it is a config problem on the specific account IP at the server end, that would solve it ..and if it is a server wide setting that they have changed recently that is causing the problem,then the problem would still be evident even on a different IP, and that would confirm to them that it was at their end..