CGMiner Question

[SkySurfer]

Hi,

I'm new to this forum and this is the only place I can post my question so sorry if this is not the apt place.

I'm using Linux(Redhat 6.4 and Ubuntu 13.04) on my machines. What I tried to do is to compile CGminer for them.
The Problem is that one machine is based on AMD  and the other on Nvidia graphic cards. As far as I understand the idea
of OpenCL it should abstract the code from the platform, right?

So my innocent idea was I complile it once and can use it on all platforms.
But what I experienced was that if it is compield agains AMD OpenCL version it works only for AMD and not for Nvidia and versa vice.
Where is the problem?

Best regards
SkySurfer