The cubes are 512x512 (3072x512). When I change the shader to display the cubemap and instead of rendering into it I load a skycube (1024x1024) it works fine. Could the problem be rendering into the cubemap? I am using the size_x, size_y, pos_x correctley (they work at resolution of 1440x900 or higher) and I set up the 6 views' arc to 90 and their angles (pan) are correct. Also, I found one more problem - I cannot render into a cubemap with sides larger than 512x512. I can load cubemaps with 1024x1024 sides but I cannot render into them. thanks for your help and let me know if there is anything else you need to know.
-Mike-