Brian,
A failing hard drive that clicks is going to be very distinctive and hard to miss. If you are only hearing "buzzing", then its probably another type of problem.
I would suggest to you that you do not have much time to mess with the drive. If the head is crashed onto the platters (cause of buzzing???), there is a potential of really causing more harm to the drive.
If that data is that important, I would strongly consider contacting Maxtor asap, and if necessary, do the data recovery service option before messing with the drive any further. Take it or leave it, just my opinion. I just hope you can recover the data.
Gary
gwinn7