Windows 7: Remote Desktop Failure Black screen

ok basically lately my remote desktop is flaky.

Scenario is.

Activated Windows 7 N Ultimate as host machine (in other room)
Activated Windows 7 Ultimate as client machine, am using it now.

If I remote desktop in after logging in locally on the host, I get the black screen for approx 2 minutes at which point it closes with an error.
If I remote desktop in whilst the host is logged out I can connect and log in fine.
If I detach from a running remote desktop session and try to relogin again, I get the black screen sympton again and have to logout locally on the host to be able to login again on remote desktop.
If I try to login locally on the host whilst the black screen is up here I get rejected due to remote desktop service been busy. I have to wait for the window to close.

any ideas what the problem is?

to add I do briefly see the login screen before it goes black. It is actually managing to connect, the error I mentioned is something like "the 2 systems were unable to connect in the time slot alloted".

ok solved it, the culplrit was networx, more info here.

SoftPerfect Research Forum :: NetWorx :: Version 5.1.7 is blocking Remote Desktop Connection.

I started uninstalling apps I didnt need, got nowhere, checked msconfig, disabled networx fixed, enabled again, broken. Then googled and found the above page to confirm it, luckily it seems I can just downgrade it and will be fine. I hope this helps others with same issue.