No fix on my end. I finally got this working myself a few days ago and I get random Push messages from other peoples accounts. It's quite strange and fun at the same time, LOL.

I think we're definitely going to need to wait on the Dev Team or other hackers before we can see Push working with any kind of consistency. It works beautifully on my iPod Touch, but on my iPhone it's just as random as you've described. Sometimes I won't even be USING Push (as in my sessions should've expired per programmed settings), and I'll randomly get Push messages from other people's IMs...