Not surprised you needed the newer kernel, only a bit surprised about the trap. The kernel internally is DOSCALL0.DLL and is closely matched to DOSCALL1.
Be aware that there are still bugs in that kernel with high memory. The worst is that high memory isn't correctly released when closing the browser, so if you open and close FF repeatedly, things get funky.
You can install one of the mozturbo programs to keep the DLLs loaded or reboot regularly.