This bug occurs on both of my computers, running Winamp 5.62, when syncing to my HTC Thunderbolt running Winamp 1.1.1. I've uninstalled and reinstalled all copies of Winamp multiple times and the bug continues.
Symptoms: WiFi Sync deletes all previously synced music and then re-syncs it, every time sync occurs. Music already on the device could have been result of a USB sync or a WiFi sync, it doesn't matter. Songs shown on the device match songs shown to be synced:
Tracks on the Android device are identical to the ones on the computer (MD5 hashes match), but in the PC client the track numbers are shown as being in the thousands on the device, only when the device is connected via WiFi. Connect via USB and they are fine. On the device the track numbers show correctly. It seems there is some sort of glitch with the track numbering being sent to the desktop by the android Winamp WiFi sync process (or in the parsing of this data by the desktop client).
Desktop: Phenom II 920, Win Vista Ultimate x64, Cisco WET610N Running 802.11n on 5GHz.
Laptop: Thinkpad X200, Win 7 Pro x64, Intel 5300 AGN Running 802.11n on 5GHz
Home network is a 5GHz n network and a 2.4 GHz g network, both running from a Netgear WNDR 3700 router. There is full access between the two.
Android: HTC Thunderbolt with Android 2.2.1
Changing so that both computers are on the same SSID doesn't affect the bug. Turning off all firewalls and Antivirus software on the machines doesn't affect the bug. Both imported media and Winamp downloaded podcasts are affected.