Without knowing exactly what operating system and version of AE down to the last decimal point and build number it is going to be very hard to tell what is going on. Is your GPU on the approved list? Have you installed the latest build of the card drivers and CUDA?
Doesn't matter. OpenGL is a tiered system and always backward compatible. AE only uses 2.1 even if your hardware may in theory support higher levels and that is just that.
i'm using quadro k4000
and my cuda version is 6.5 (showed in AE)
I think I have installed the latest version.
Thanks Mylenium for your fast respond