Some time ago I accidentally hit my powerbook against the edge of a table, creating a minor dent on the corner of the casing behind the power jack. It seemed to be only a cosmetic problem, I had no problems at all for almost a year. But recently I noticed that when connecting the AC adaptor, sometimes I had to fiddle around with the plug before it will light up or sometimes the lighting changes from green to orange with slight contact to the plug or the wire. But it has only been a minor inconvenience... I'm not sure that this has been due to the dent incident since it was fine for so long. The dent doesn't seem to have affected the jack itself and I have had similar plug/jack problems with other Apple products. Anyway, my PB is under Applecare and I brought it in last week for another issue and also mentioned this problem. I just got a call from a technician, recommending that I replace the bottom casing of the laptop for $160. I asked if it was really necessary, or just cosmetic - and he replied saying something I couldn't make sense of about the current, a rubber band how it was safer for the logic board. So can anyone who understands this better explain if it is really necessary to replace the casing?