I think I lost my $5 offer due to testing a .CA domain transfer (and it displayed $5) but the domain was already at WHC so I had cancel and manually 'push' it.
I guess that used up the promo and since then I no longer see $5 as a payment. Thought it was just a display error, but it also shows up as full price in my cart.
I never have any luck with WHC promos as they always seem to get used or disappear on me for some reason -
@FM can attest to that one.