I had problews with my phone rebooting with 32wd_to reason (bugs #6334 and #8229).
I had to disable deep sleep in /etc/pmconfig which caused reduction of battery life. To have somehow manageable time of running I have then enabled SmartReflex - and even though my device had reboots, they were never caused by SR.

I have had SmartReflex enabled on all available firmware F original, PR1.0.1, PR1.1, and PR1.1.1 - no problems with it.

Usually I charge by wall charger, but IIRC I have charged once over USB; this was however from my desktop.

Maybe this is reason of your prolonged charging - maybe your laptop does not provide enough power. If you have desktop, please try charging from it.