FireWire connection prevents startup of G3/BW Macs?

Dennis Stillwell describes a startup problem he had with his new 400MHz G3/BW (with the internal SCSI drive) - and a surprising solution:

"The G3/BW worked perfectly for about a month. Then, five days ago, the computer started to freeze on startup, just before the extensions would start to load. Eventually, the only way I could get the computer to boot was to use the System CD that came with the computer. I determined the problem was centered around the FireWire extensions. If these were in the Extensions folder, the computer would not boot. I know that before the main extensions start to load the computer checks the hardware for errors (RAM, PCI, USB, FireWire, etc.). So I started to look at the FireWire hardware in the computer.

I found that if the screw next to the FireWire ports on the back of the computer is too tight, it pulls on the small connector box that connects the FireWire ports to the main circuit board. This then pulls on the connector that is connected to the main circuit board and apparently causes one or more of the connectors to touch. This then causes the computer to freeze on boot up just after the computer runs its tests.

I loosened and tightened the screw to verify this problem and the computer would freeze when it was tight and work perfectly when it was loose. I figured that it took a month for the plastic on the connector to become flexible enough to cause this problem. But this means that more people could start to have the problem once the computers become a little older."

Update: I have now received two other reports of this problem. Both confirm that the fix suggested here works.