Land won't show up...

So I installed everything ok, and since I play oblivion with about ten million different mods, I disabled them all. I now have the following data files enabled...

Oblivion.esm
Morrowind_ob.esm
Tribunal_ob.esm
Bloodmoon_ob.esm
CNME v1.4.esp

And that's all for now. So I get on the boat at anvil that takes me to seyda neen, and everything displays properly until I try to exit to Seyda neen... then oblivion shuts down and gives me the old 'Oblivion has encountered a problem and needs to shut down' message.
If on the off-chance I can actually make it into seyda neen, there's no land, or buildings, but the rocks, trees, doors and people display properly. If I go over to one of the doors and enter a house, the interior displays perfectly.
What is causing this and how can I fix it?
Thanks in advance for your help!

EDIT - I have fixed the problem by setting my video settings to low (which made the land display again for some reason) and then bringing them back up to where I usually have them bit by bit (saving and loading with medium, then high texture sizes and changing the resolution bit by bit) and now it works properly. So I'm not sure what was going on there...