Ext3 users - Jul 2008 - What used to be a directory is now a 0 length file - recovery possible?

Hello,

I have a server that mounts ext3 partitions from an EMC SAN.  A few days
ago, EMC upgraded firmware on the SAN, and it appears they did so
without first coordinating a filesystem unmount.  The result is that
where I once had a directory which contained subdirectories underneath
it, I now have a 0 length file.

I am by no means a filesystem expert, but I thought it might be possible
to recover the data by setting the inode type back to directory?
Hence my plea for help from you, the experts!

Not all of the data on the filesystem is missing, just this one
directory and everything under it.

Any advice will be greatly appreciated.

Charles