Ts-gateway and sharepoint

[P-POD]

Help please

I have set up a working ts-web and ts-gateway for local and external
use in my lab environment and it works a treat.
I want to take this to the next level and integrate Ts-web into
SharePoint Services to give me some flexibility, I have been able to
successfully add the new web parts into SharePoint and all works fine
on the local network when bypassing the Ts-gateway. The problems start
when I want access the remote apps through the Ts-gateway, I can
access my SharePoint site from the internet and my remote apps are all
present, if I try to launch any of the apps I receive the challenge
from the ts-gateway to authenticate to it and my TS, this is where it
fails and just keeps saying login failed.
I have stopped SharePoint and started the default TS web site and
reconnected through the ts-gateway with no problems?
One thought I have is that it may be related to the way SharePoint
authentication is setup, if I manipulate the authentication in IIS 7 I
can receive a different error.