WIZ750SR-110 GCC?

Has anyone had success building the reference app for the WIZ750-1xx devices with GCC? It is too large for the free Keil linker. I can get it to compile and link, but it does not work. To clarify, I am trying to use uVision 4 or 5 with GCC tools in place of Keil.
OK, tried the Eclipse project too. Same result, builds but does not run.