iphone 4 multitasking help required

Recently purchased an iphone 4, but one thing is really annoying me, ive ibetmate running, along with one of the fixed odds betting firms apps as well, the problem is when im multitasking and switching between apps i have to log in to each time i switch between apps. When i had a htc magic i could log into betfair lite and a fixed odds site and i remain logged in, anyway around this on the iphone 4? thanks in advance.