I hate my iPad when, randomly, it disconnects from my home wifi and stalls whatever I was doing so it can reconnect. This happens once or twice a week and lasts for ~15 seconds.
I hate that I don't have time to play with all the free apps that appear to go on sale daily.
I hate that the PC or MAC version of a game is $70 and the iPad version only $9.99 or less.
I hate doing something the hard way because I didn't know the app could do that easily. (eg the web browser in Goodreader works with Rapidshare)
I hate that my Wii balance board won't talk directly to my iPad (so I could sell the Wii)
I hate that I had to jailbreak my iPhone so I could tether it to my iPad so I wouldn't need to pay for another 3G account.
I hate that skype turns my iPad into a free phone.
I hate waiting for apps to go HD
I hate I have gotten more playtime out of a 99c app than almost every PC game I own (except Battlefield 1942 now that would be something on the iPad)