Ok, I just tried it again and I just can't get it to crash, even with the oddest settings.
Here's the setup I used on PC:
Steem.SSE.3.9.4.Win32.D3D
tos206us.img (find attached)
ST Model: STE
Memory Size: 1MB
Please note that pressing [ESC] quits to desktop from the title screen. So make sure to setup the joystick input properly as the game expects the fire button to be pressed to start. I've attached a screenshot of my settings, it uses the cursor keys and space when numlock is off to emulate the joystick.
I've also compiled a version with a separate data file, the new disk image (RODNEY_DISK_ONLY.zip) is also attached. This version will only work when started directly from the disk image, so don't copy the files to an emulated hard disk.Let me know if you get it running.

Edit: New version in first post.