When you upgrade not only is the firmware changed but all your app's and settings have to be reconfigured and integrated into the upgrade during the process. This is in an attempt by Samsung to retain everything on your phone so that you do not have to set it all up again after the change.
If you stop and think about the millions of app's and the myriad of
settings that this has to take into account then maybe you can
understand why there are sometimes problems with phones after new
firmware is installed.
Some of these problems are caused by app's that are not suitable for the new firmware. Remember, not all app's on the Play Store may be compatible with your new firmware yet.
Other app's, that work on your existing firmware, have to be updated
for the new one, if possible, during the change over. No mean feat...
particularly if you've moved apps to your SD card as the system folders
for these apps will usually remain on your internal storage and this can
cause big problems with separated app and data. Especially on the
These problems can manifest themselves in all sorts of ways... from non compatible app's continually running and causing high battery usage and over heating not to mention eating up your storage with constant log or dump files. Settings that are giving Forced Closes or very long screen lags. High RAM usage or screen freezes and shut-downs
can all occur because the user app's or data have not, or can not, be
integrated successfully into the new framework automatically during the
Also, the downloaded firmware update itself may have been corrupted.
This can easily happen with OTA, (Over The Air), updates where an
interruption has occurred with the download. This has also been reported
by some who have used the Samsung PC suite, Kies.