Some of the problems that LG Optimus S owners have had after updating to Android 2.3 include a failure of the phone's battery to recharge, the inability to connect to data, a message that the microSD card is un-mounted or removed and when connected to a PC, the device is unrecognized by Windows XP, Vista, or Windows 7. Also, the predictive text fails to work on the Android keyboard.
Click on the sourcelink for ways to workaround the issues until Sprint can disseminate a bug-free version of the software. Hopefully for owners of the LG Optimus S, that won't be too long from now.
source: Sprint via AndroidCentral