It's probably the texture coordinats. Blocks and models use different texture registers (for whatever reason), so you'll have you change this...

In the vertex shader definition, change:
float2 texcoord0 : TEXCOORD0
to
float2 texcoord0 : TEXCOORD1
or even
float2 texcoord0 : TEXCOORD2


..That should work. You'll have to try it.

xXxGuitar511
- Programmer