When logging into Gmail, it will stop at the "redirecting" phase. When logging into Facebook, it will ask me to enable cookie even if I've already enabled it. This problem occurs when I write my own code at http://xizhizhu.blogspot.com/2009/06/develop-your-own-web-browser-using.html, or use the sample provided in QtSDK-2009.02, or Arora 0.7.1.
Does this bug still occur for you with say the Qt 4.6 alpha release?
Tried with both 4.5.3 and 4.6.0 and I could not reproduce the problem. Please reopen if the problem is encountered again or if you have more information on how to reproduce the it.