Since Apple introduced iPhone OS 3.1.3 last week, we've found a number of complaints about two issues with the firmware update.
Although the update was supposed to address issues with iPhone 3GS battery life, it appears to have caused battery problems for some users. According to users on Apple Discussions under the topic iPhone 3GS OS 3.1.3 battery percentage fail?, the iPhone's battery indicator can rapidly swing between 7 and 25 percent before suddenly going back up to 24 percent after the point upgrade.
Some users also complain that battery life is unusually short after the firmware update, lasting some 3 to 4 hours with the iPhone possibly running hotter than normal.
Playlist sync problems
Users are complaining about playlist sync problems under the topic Anyone who has installed the new update (3.1.3): Any issues with it? on the iPod Touch. In this case, the files are copied onto the device, but the playlists themselves are either missing or empty.
According to posts under this topic, the problem seems to only affect smart playlists and seemingly only those with more than one criteria. Suggested temporary workarounds include making your smart lists less "smart" by removing criteria down to a single iTunes field, creating list names without spaces, or deleting and adding them again.
Apple hasn't provided a solution to these problems yet, although it is likely that an update to iTunes or iPhone OS may address them. (This isn't the first time users have.)
Are you experiencing problems with this recent iPhone OS update? Tell us about it in the comments.