glDrawPixels and texturing

I have a quite odd problem with glDrawPixels on NVIDIA hardware.
I use DrawPixels to draw a background image before rendering a 3D scene, in fact just one object. If the 3D object contains a texture, DrawPixels don’t work properly. After some investigation, i find it don’t work because texturing is activated when i called DrawPixels.
i am quite a bit surprised, i know that fragment operation are done wheh you use DrawPixels, but i never see anywhere that there is an interaction with the texturing.
Does anyone have an idea, or have found a similar problem ?

glDrawPixels generates fragments that are passed down the pipe and are treated just like any other fragment. So if texturing is enabled, the fragment will be affected by the texturing.