In my Paydirt Football league, I keep getting a message that I have a pending trade request, but I don't see anything in the trades screen.

i keep running across this as well

Could it be you had gotten a trade from someone and it cancelled because of another trade? I had a similar instance this week is all.

It would tell you if the trade was canceled due to another trade. My guess is, the coach who originally proposed the deal decided to withdraw it.