Non-existent problems reported

[Nintynuts]

First I was getting a warning for this line of hlsl:
r3 = mul(r0.xyz, (float3x4)gWorldToProj);
saying:

Implicit truncation from 'float3x4' to 'float1x4

Which is clearly wrong, since it's explicit casting, so I cut the cast type to give this (which should cause the warning):
r3 = mul(r0.xyz, gWorldToProj);
which ended up with this error:

Variable 'oj' is not declared.

Which looks like it's ignoring the length of characters I cut from the start of the variable name (it's using the start index before I cut for the token start, rather than after)

When I paste the cast type back in, the warning doesn't return, but the invalid error remains.

I don't always get the initial warning though.