hm... Warranty replacement is not an option with a broken warranty seal ;-)
I know of voidmans site and have already tried shortening pins 9 and 10 before switching the wl500g on but this didn't change the situation.
So I thought it would be better to short the exact same address lines as mentioned in voidmans description (pin #9 and #16 on the am29lv320dt). I succeeded in making a connection (it's not easy but possible to solder hair-thin wires with the right tools) but unfortunately the situation stays the same.
Well, I guess the unit is really dead - although I really don't know why...