BB Torch :: 9800 Occasionally Will Not Charge

I am running into an issue, periodically, where my Torch 9800 appears to be charging when placed within my dock, but loses battery life (appears to actually drain the battery) over the course of an evening if shut off. This never used to be the case, as the device would charge regardless of whether it remained on or was shut off. I also cannot rely on the flashing light (when put in charger) as the device does not do this on occasion, even when it does appear to be charging. I am wondering if this is a common occurance and whether there is anything I can do to ensure this problem is fixed, as I would like to rely on my Torch as an alarm clock, but need to know that the battery will not die over the course of an evening.