Sometime on Jan 29, Satish Alwani assembled some asciibets to say:

When i do major transfers to this box, the machine ends up hanging.

Average transfer speeds in excess of 7000K or even higher than 10,000K at times.

Your hang has nothing to do with the spurious IRQ7. IRQ7 is the parallel port interrupt, and it generally means that the interrupt was generated, but no one sent it. This can happen for example if you have some static near the parallel port pins.

What network card do you have?

Philip