This:
"You have carried out too many actions on the Market in a short period of time. Please wait and come back later. To avoid this problem, ease up on the Market."
Shows up whenever I try to access the Market, or any sub-part of it. All I did was put about 100 or so cards on the market 
Some was done on the web, some through the iPhone app. How long must I wait before I can use the market again?
This is what happens when you over buy or sell on the market in a short amount of time give it anywhere from 8-24 hours and it should be all cleared up and ready for you 
