would it be ok to use lube like WD40 on the prongs?I wouldn't!
I suggest you pull each piece of equipment out where you can get a good visual look as to exactly what is going on when you try to insert the IEC connector into the IEC plug on the equipment. Is it the contacts, or is it the fit of the two bodies of the IEC connectors causing the tight fit.
To be honest most guys would love a tight fit of their IEC connectors.......
[url]http://www.psaudio.com/ps/products/description/trio-a-100-power-amplifier?cat=audio[/url]
Jim