Critical malfunction in current firmware (Android 2.3.6)

I have the phone for half a year and agrees to all the studs, what is said about it here only; rapidly, wonderful display etc. However, the phone since before last firmware update a serious malfunction: It turns out easy and then immediately back on, but then it naturally remains at the PIN entry - not operational - are. That happens to me from time to time, but at least once a day, sometimes four to five times per hour. I have long searched in forums, to know a lot of mistakes, but all the other solutions do not help, whether reset clamp to factory settings, battery, uninstall apps, switch off the WLAN. In this behavior, there is in my opinion two problems: First, that you can not be relied upon to be available because you can really be sure never that the phone is on; Second, one can in this case, the boot sound not leave, not even with apps like Silent Boot because the phone crashes just off and restarts. Can happen so that the phone losdingelt in an inappropriate situation. On a tip from Amazon I called the German Samsung support when I had the fax thick - who confirmed to me that this is a known bug that should be fixed in the next firmware update - at the time there was unfortunately no information. So: who is dependent on a reliable working phone, which should make up the next firmware update to steer clear of the Galaxy S2. If that's actually not sooo important, can also now access.