I was also having the same problem in fluxbox (see bug #531339 for screenshot). In the last days, anyways, with the updates, the behavior has changed, but is not entirely fixed. I can report the following situation:
With AC adapter:
* Start g-p-m. No problems/warnings on console during the entire lifetime of g-p-m
* The icon displays OK in the systray.
* When switching to battery, the icon goes and come back about 3 times, to finally dissapear
* When switching back to AC, the icon comes and go about 3 times, to finally stay
With battery:
* Start g-p-m. Got a warning (the only one during the lifetime of g-p-m):
(gnome-power-manager:6329): GLib-GObject-WARNING **: value "-nan" of type `gdouble' is invalid or out of range for property `percentage' of type `gdouble'
* The icon displays OK in the systray.
* Same behavior as explained before with AC adapter, but now icon stays while on battery, and hides when on AC.
I was also having the same problem in fluxbox (see bug #531339 for screenshot). In the last days, anyways, with the updates, the behavior has changed, but is not entirely fixed. I can report the following situation:
With AC adapter:
* Start g-p-m. No problems/warnings on console during the entire lifetime of g-p-m
* The icon displays OK in the systray.
* When switching to battery, the icon goes and come back about 3 times, to finally dissapear
* When switching back to AC, the icon comes and go about 3 times, to finally stay
With battery: power-manager: 6329): GLib-GObject- WARNING **: value "-nan" of type `gdouble' is invalid or out of range for property `percentage' of type `gdouble'
* Start g-p-m. Got a warning (the only one during the lifetime of g-p-m):
(gnome-
* The icon displays OK in the systray.
* Same behavior as explained before with AC adapter, but now icon stays while on battery, and hides when on AC.
Hope this helps.
Rodrigo