Haha! Thanks CR. I'll assume I'm not alone in this minor but noticeable gripe then. Hadn't thought of wedging it but I do that as a fix with ill fitting wood screws when no other solution is handy
Oddeophile: The issue is at the IEC connector in the sub's amp, not the wall socket. I'm using the JLA supplied power cord which seems to be a loose fit in the receptacle on both my units. I have no complaints with the performance apart from the relatively insecure fitment of the supplied cord.
I probably would have suffered this as a minor inconvenience but the topic came up in this section so I asked.