Problems with G-tech drive

Hi all,

I have a G Drive Q 1Tb connected to my MBP (late 2009) via eSata and am using it mostly to store files for FCP and Motion.

Every once in a while the drive will just freeze (it's still there on the Finder, but the application that was using it somehow "loses" it and asks me where it is - it happens while exporting with Compressor or rendering with FCP -) or the LED on the Express Card will stay on and the Finder will then freeze, forcing me to reboot by holding down the power button. This would happen even if the drive is not in use.

So, I don't know what I am doing wrong here. I turn my hard drive on before the laptop. I also eject it on the Finder before shutting the computer down. I turn off the drive whenever it's not in use.
I have changed this drive once already because it was unmounting itself and have had this new one for maybe 2 weeks.

I was expecting this drive to be reliable and able to withstand demanding applications.

If anybody has any suggestions on what to do...

Thanks.

Olivier