Error message: Filesystem has incompatible feature enabled

[Rob Myroon]

Hello parted gurus,

I tried to move an ext3 linux partition to free space on the hard drive 
and received this message.

"Filesystem has incompatible feature enabled"

I am using Redhat Enterprise Linux 4 ES
parted rpm is parted-1.6.19-1.EL

Why can't I move my ext3 partition? What is this mysterious incompatible 
feature and why is it enabled? Can someone help me out please?

Thanks,
Rob