*Update as of 25 Jan 2013: Two months after this was reported, Samsung Singapore posted on their Facebook page today and apologized for yet another troubled Jelly Bean update which was apparently not meant for release in Singapore. Below is their full statement:-
Dear fans, the recent software update for GALAXY S III, Jelly Bean 4.1.2 (XXELLC), that some of you might have received was not meant for released in the Singapore market. We do offer our sincere apologies for inconvenience caused. We will keep our fans updated when the software is ready.
*Update as of 21 Nov 2012 10 a.m: Forum member, unseen, appears to have all the issues mentioned below in his or her Galaxy S III device. unseen wrote in a post that the display would flicker by itself, and the phone has to be restarted regularly to address the sluggish performance. Communication apps such as email and WhatsApp are also not functioning properly despite having mobile data connectivity.
Earlier today, we reported that early adopters of Windows Phone 8 devices are having issues of random reboots and short battery life. It has come to our attention that they are not alone; local users of Samsung Galaxy S III (non-LTE) have reported similar problems on their devices after updating to Android 4.1 Jelly Bean.
The first reported issue was by forum member, dawndy89 who found his phone to be laggy after the update on 1st November. Several other forum members (1) (2) (3) (4) (5) also encountered sluggish performance on their phones.
Another forum member, Emospence, wrote in his post that his Galaxy S III could not charge properly; the battery level increased a mere 10% after an overnight's charge. Strangely, he noticed the phone would charge normally if it is switched off. In addition, he realized the battery drained faster from over 60% to 15% in 6 hours while the phone was in idle mode.
There seems to be an issue with the Galaxy S III turning its display on randomly. Forum member, Lost_Found realized his phone's battery percentage dropped from 22% to 5% overnight. The battery usage statistics revealed that the display was turned on randomly throughout the night. Another forum member, cutebeng, also experienced the same problem.
Two other forum members, kohkindachi and stfms, claimed that their Galaxy S III devices restarted for no apparent reason. In the post, stfms stated that his phone restarted at least once a day while kohkindachi's Galaxy S III kept restarting.
We've reached out to Samsung Mobile Singapore on this matter. A Samsung spokesperson replied that the company is aware of the isolated reports of issues with the Jelly Bean upgrade and is investigating.