CRM 4 - Receiving this when trying to save - "A Microsoft Dynamics CRM window was unable to open, and may have been blocked by a pop-up blocker."

I am currently extending a CRM 4 system (upgraded from CRM 3) on Windows Server 2003. I do my development on a VM and all is working fine there. However I put my changes up on to an integration server and now am having issues.

When I try to save any entity I get the following message

"A Microsoft Dynamics CRM window was unable to open, and may have been blocked by a pop-up blocker. Please add this Microsoft Dynamics CRM server to the list of sites your pop-up blocker allows to open new windows: "

I get this message when using IE on the Server (Windows 2003, IE 8) and from a client Machine (Windows 7, IE 9)

There is anothe开发者_如何学Gor organisation on the server and I can save entities when I use that organisation. This made me think that some of my code may be causing the issue but when I try to save an entity with only a name field and no custom code around it I still get the message.

This system doesn't use CRM for outlook

I have read up quite a bit about this error on the internet and have tried the following to remedy the situation

Turning off pop-up blocker

Adding the server to the Trusted Sites list

Upgrading to Internet Explorer 8

Clearing all temporary data from IE

Completely uninstalled office (including Outlook) from the server

Made sure there are no toolbars in use (or installed) on the server

At the minute I am using an administrator user, as mentioned previously this user can save in the other organisation, but not my new one. I cannot add another user because when I try to save it I get the pop-up blocker message (arrgg!!!)

Anyone have any ideas?

Thanks, Neil

Hmmm, was custom code. A plugin was calling a webservice which wasn't set up correctly on the integration server.. Pays to look in the event logs