.........checked with Apple yet about the issue? Maybe the newer iOS on the 3GS isn't fully compatible.
I just upgraded from 4.3.5 on my 3GS to 5.1.1 and installed iCloud......finally! My computer is a Windows 7 PC.
There are now problems with setting Calendar Alerts. Some were gone and reconfiguring them for first Alert 2 days and second Alert 1 day was very difficult but successful after many, many attempts......it took several hours.
Is this a known glitch?
All in all the install seems pretty successful except for the above-mentioned problem and the loss of photos that were not on Camera Roll (no problem as they are on my computer).