Help!! 10.7.5, keeps ejecting external drive when backup and coping files.

Osx 10.7.5, keeps ejecting my external drive when i run backup on time machine and when I'm coping large files. Any one know how I can fix this?

Thanks.
chris

It might help us to know which Mac you are using. Having said that here are a few things that might be worth checking. I'm assuming this is a USB drive but most of this is applicable to other types of drives as well.

1.Have you tried a different cable in case the one you are using is starting to fail?
2. Try using a different port if possible and see if that makes a difference.
3. If this is a USB drive does it use one of those double-ended cables so it connects to two USB ports? Many of those can be problematic. If the drive has an option to power it from a standard electrical power chord try powering it that way.
4. Are you experiencing this problem with other external drives?

Hi Slydude, Thank you for getting back to me.
I'm using a late 2008 macbookpro with osx 10.7.5 and an G-technology 2Gb external hard drive with a FW 800 cable.
I've been researching online and all I found that worked for coping files was a terminal entree " dot_clean" that has work for some files. But still I'm having trouble on coping the rest and I can't even do a backup time machine to the external HD.

An suggestion, on how I can fix this??

I have that same machine and haven't had issues with the Firewire ports but I don't have many Firewire drives anymore. Are you able to run Disk Utility and verify the drive? I can't quite decide if this smell more like a hardware issue (controller board on the drive, etc) or directory issues.