Thanks for all the fast replies and sorry for this late one, I just got off the phone from BT whom now admit the line fault was their doing efter an hour of 'your extension wiring is faulty and is not done by BT...' when I've got the modem hooked into their test socket.... Anyway, I digress.

User137: Thats what baffled me: the opengl headers come from the same package and are thus identical on both machines - why they differ is beyond me O.o

Paul: Yes, the glGenFrameBuffers() is in the main program code and you're right in including cthreads as it is a common unit often ommited form some code that causes issues later. However, in this case its inclusion seems to have no effect and the behaviour GDB reported earlier continues to occur.

After now 5 days of tweaking this and searching high and low I've found that in C/C++ and other such languages, glGenFrameBuffers is a pointer and must be set to the actual procedure. Is this the case with the header files in fpc? And if so does anyone have any ideas where I might find some example code/documentation?

Thanks