How to get iTunes to reconnect after buffering?
It is not possible to change the time-out within iTunes easily. But there is another solution to your problem.



Create a playlist of an internet stream


Go to the iTunes Internet tab.
Select your radiostation
Get Info (File -> Get Info, or CommandI)
In the info screen, select the Summary section
Right click the URL next to Where:, 'Copy URL'
Now open this stream (File -> Open Stream, or CommandU, paste, OK)


This should create a new playlist "Internet Songs". As it only contains 1 'Internet Song', this should keep your from skipping to the next stream.