.......noticed a few times, back end was loose on corners, and bit of turn in oversteer, Whoops tyre pressures all over the show 
Same here, mine is a rim leak on one wheel so without a refurb I'm buggered.
It will stay at the same psi for a few days until the wheel rotation lands on the bad bit and it will drop to around 11psi overnight. I'll have to get it sorted as it's pissing me off keep inflating it. 
I failed my walk-around checks this morning as it was down again and I felt it rather than see it. 
Usually its the bead, a good tyre fitter would grind down the corroded area and apply sealant tot he rim before tyre fitting (some just lob the sealant on the corrosion and of course, it then leaks)
Yeh sorry, that's what I meant, the bead seal to a flakey rim, but you are right in what you say as the rim needs dressing to cure this. 
I have the same, the fronts can easily loose 5 PSi over a week sometimes.

I've got a set of new Kuhmo's on early F/L Elite Alloys, but I much prefer the later ones. I plan to go to WIM to get them to swap over the tyres and double check the corrosion on the rims. Also time it had a Geo-session as well.
Can't wait to get rid of the shite Nexen's
