convert cg 1.2.1 to 1.4 compiler

Hi! I am facing a difficulty.
I removed the cg 1.2.1 compiler and installed the cg 1.4 compiler. Is there any changes in cg 1.4 compared with cg 1.2.1? I think that I should change the grammar or some other syntax in cg code.

The code in the cg 1.2.1, as follows.

//**********************************************
// Input variables

struct appdata {
float4 position : POSITION;
float4 color : COLOR0;
float4 texcoord : TEXCOORD0;
};

// Output variables

struct v2f {
float4 position : POSITION;
float4 color0 : COLOR0;
float pointsize : PSIZE;
};

//########################################################################
// scrPar encodes UNIFORM 4 parameters used to calculate the screen size
// of a splat: { nearplane, height/height of nearplane, (f+n)/(f-n), -2fn/(f-n)}
//

v2f main(appdata I, uniform float4 scrPar)
{
v2f O;

float4 P = mul(glstate.matrix.modelview[0], I.position);

O.position  = mul(glstate.matrix.mvp, I.position); 
O.color0    = I.color;
O.pointsize = max(1.0, I.texcoord.x*scrPar.y/abs(P.z));

return O;

} // main

//**************************************

If using the cg 1.4 compiler, there is no compiling error or linking error. However, I can not get anticipated results.
In the rendering stage, I want to see the resizeable point. but i just could see glPoint.

But using the cg 1.2.1 compiler, there is no problem.

Many thanks in advance.

Best Regards,
DB

Are you using the same profile in both cases? Could you submit the resulting code after compilation with both Cg 1.2 and Cg 1.4? It might also be a good idea to try the Cg 1.5 beta:

http://developer.nvidia.com/object/cg-toolkit-15beta.html