Safari loads freezes loading webpages very slow on iPhone 4

Hi!
I have a problem with Safari on my iPhone 4 (4.2.1). Since I upgraded to 4.2.1 a week ago Safari is very slow and in 80% of time wont load webpages with first time when in 3G mode with strong bars. Well it loads them but very slowly (It takes approximately 20-30 seconds to load google or other pages). Maybe it would be more precisely to say that it starts to load, than the blue progress bar just stops at around 1/2cm and than after 20-30 seconds it actually starts to open the page and the blue progress bar continues to move. Sometimes (not often) after those 20-30 seconds I get message that page cant be opened cause server stopped to respond...
What is important to my mind is that if I press reload while Safari is loading a webpage it opens fast as it should. So it usually works with second try.
Since I noticed this problem after I upgraded to 4.2.1 I think those two things have connection (4.2.1 and Safari problem) but I might be wrong.
This is happening in different locations around the city and it is not problem with coverage...I have three, four or sometimes even 5 bars 3G.
Anybody having the same problem or can help me with some advice?
Thank you!
Mac Mini Mac OS X (10.6.6)