Texturing Problem with large mesh

[UNCCheezy]

I'm creating a level for XNA with XSI. It's a mesh grid 3000x1800. When I go to texture it, I can only see it if I have the texture editor up. as soon as I close it, then I am unable to see the texture on my mesh, in other words, it just goes back to untextured. If i scroll the mouse back over the texture it loads it back up. Is this a problem with the large mesh size?

[moose o death]

have you set up your shader?

you need three things for a textured mesh

shader
projection
texture

shader is applied on mesh creation, but wont have anything texture wise attached to it.
if you don't do all of those things the texture will not work.

any reason your designing such a large mesh though?