updated 04:20 pm EST, Mon February 8, 2010
Originally meant to solve battery problems
The iPhone 3.1.3 firmware has introduced problems for some people even as it has fixed them for others, say complaints on Apple's support forums. Most critical is an issue with battery life, which can suddenly become erratic. A phone's battery meter may potentially swing wildly, for instance going from 25 to 7 to 10 percent, then jumping back up to 24 percent.
Worst-case scenarios may see phones losing hours of power, and even running unusually hot. The v3.1.3 firmware was in part meant to correct battery meter trouble on the iPhone 3GS.
Another major problem involves iTunes playlists, which in some cases are failing to sync properly with the iPod touch. While files will copy over properly, playlists may be empty or simply absent. The glitch is believed to affect only smart playlists, and potentially only those with multiple criteria. Temporary workarounds may include reducing criteria to a single field, and/or deleting and remaking previous playlists.
Apple has yet to formally address or fix either of the cited errors.