lightnshade
Member
- Apr 9, 2013
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Kies told me my firmware was up to date too but it became clear to me that there are other versions which are effectively the same (just more stable!) and yesterday I took the plunge and moved from XXELLA to XXEMB5 - I've been freeze-free since! 
My S3 is locked to o2 (I tried a "3" SIM and it didn't work) and is a stock model - the process still worked fine even though the guide says make sure your phone is unlocked.
This is the step by step guide I used as I'm a relative noob to this too - Galaxy S3 I9300 Gets Official Android 4.1.2 XXEMB5 Jelly Bean Firmware [How to Install] - IBTimes UK
The link to the main file needed didn't work, so I just googled "download I9300XXEMB5" and found it very quickly.
Good luck!

My S3 is locked to o2 (I tried a "3" SIM and it didn't work) and is a stock model - the process still worked fine even though the guide says make sure your phone is unlocked.
This is the step by step guide I used as I'm a relative noob to this too - Galaxy S3 I9300 Gets Official Android 4.1.2 XXEMB5 Jelly Bean Firmware [How to Install] - IBTimes UK
The link to the main file needed didn't work, so I just googled "download I9300XXEMB5" and found it very quickly.
Good luck!
Well I'm using I9300XXELKB, and no other updates are currently available. But the freezes didn't start after this ROM update, which dates back to January.
I was rather thinking of non-Samsung ROMs.