My phone is a UK T-Mobile supplied SGS2, about 11 months old, on Ice Cream Sandwich. I can't remember if the problems I am reporting occurred prior to ICS.
1. Almost every time a new page is loaded in the web browser, either from clicking on a link, or from my bookmarks list, or from a Google search, the new page loads and the screen brightness changes to very dark, and I have to press and hold the notification bar to allow me to change the brightness back to normal.
2. Today a recurrence of a previous problem. The web browser is unusable, and I have to use Dolphin instead. Whenever I scroll down a page, there is only a short delay before the browser scrolls back up to the top of the page on its own, and won't even stay at the part of the page I'm looking at if I am touching the screen to try to hold it there. I thought that the last time I had this problem, it was solved by clearing the cache. I couldn't find how to do this, but installed an app called Easy Cache Cleaner, but this didn't seem to make a difference.
Any help gratefully received.