Just a couple of quick suggestions that may help somewhat. 

I've had performance gains with the code suggested above

  WHERE (YourDate >= @FromDate OR @FromDate IS NULL)

by changing...

This is bordering on getting off topic. The record with the old date represents the last group of files that were sent to a client which we retain the record...

Thank you for your response.  I do see what you are getting at though and do something similar on a different project.  The scope of this one is a bit...

I think it is most likely having problems updating because it is thinking that it is a derived column thanks to the alias even though the alias is the same...

You could use a single table for this, but where's the normalized relational fun in that?  This would make grouping and subtotals a little easier and more scalable...

Here is a stripped down copy of the actual procedure which I would like possible improvement suggestions for.  I have removed extra columns, validations and error handling...

Yes I am fully aware of @@Identity, which isn't the problem here (I use scope_identity() anyways because the last identity inserted isn't always the one I need!)

I read back...

Thanks John.  I talked to my network guys and confirmed that the database server has it's own disks on the SAN.  They also (in a rather untimely manner as I've...

The insert still seems to be working normally thank you.

With regards to Jon's post I avoid cursors like the plague (whether by misinformation or peer paranoia is open to debate...

The T-log and data file are both on the array and other inserts and updates are working normally. But now I'm really confused because suddenly the insert is working fine and...

This is a new table created with no indexes/pks/constraints/etc.  Originally was a temp table in a stored procedure.  Created an actual table for testing in QA. There are no other...

Machine: Windows Server 2003 SP1 Intel Xeon CPU 3.06GHz, 3GB of RAM

T-Log: on mapped Drive Array currently 530MB in size (tempdb is 500kb in size).

V-Scan: Norton is on machine but only scans...

None at all.  I stripped it bare trying to eliminate all possible suspects.