I have a Pixi Plus with the same issue and am in the initial stages of troubleshooting.
While on the TS, the battery charges to 100%, then overnight, drops to 83%.
I'm testing it on the AC charger now to see if the same thing occurs when plugged in directly. Tonight I will swap batteries from my wife's Pixi and try it on the TS again.
Observation: when plugged directly into the AC charger, "0" battery current is indicated, but when on the TS, an amount of battery draw is displayed. This could indicate that, despite being on the TS, there is a load on the battery whereas, when on the AC charger, the charger output is powering the phone (?).
Maybe the battery current monitoring is not enabled when on the AC charger (?).
More info: The battery was charged to 100% on AC. I then put it on the TS and it began to discharge (it's down to 94%). I find this strange because, in the past, I have put the phone next to my bed (not charging) and in the morning, the charge was still 100%. Why is the battery discharging when on the TS?
Do a search for "palm pixi battery discharging on touchstone" - you'll be surprised.
I have cleaned the contacts - no difference.
But... why doesn't it happen on my wife's phone? She is using a different charger and TS - no preware.
More testing to follow :-)
Later: Not sure why, but it seems to be charging normally on the TS now. I swapped-out the AC charger that powered the TS and it worked normally, so I thought the first charger was defective. I then put the first charger back on and it seems to be working.(??) It charges up to 100% then depletes to ~94% and begins to charge again.