I just realized that I'm not able to unbind any VBO...
Calling BindBuffer(<some>,0) causes InvalidOperation error.
WinXP, Catalyst 9.5, Radeon 2400HD.
I'm using VAO storing all required VBO attached so I really didn't need to unbind any VBO until now.
But now I'm trying to use PBO. If I don't unbind PIXEL_UNPACK_BUFFER, then I'm not able to call glTexImage* to initialize any of my textures after that.
Did anyone experience such problems?