Spanned VMFS Volume: Bad disk alignment on 2nd extent

We have a VMFS5 Datastore that was recently expanded to 1.5TB from 1.0TB by adding a second extent LUN like so:

All of the VMs in this datastore are Windows 2003 that have had disk alignment fixed.   Reads/writes prior to datastore expansion were 90+% aligned.

Now that the first extent LUN has filled and data is spilling over to the second extent LUN,  writes to that LUN are 80+% unaligned!

Our NetApp filer reports reads/writes to the 1st extent LUN are still mostly aligned:

But shows reads/writes to the 2nd extent LUN are mostly unaligned:

I can confirm that:

• Both partitions are formatted VMFS5.54 with a starting sector of 2048, block size 1MB
• All VMDKs in the datastore are Windows 2003 NTFS,  starting sector 32 and block size 4KB

My questions

1. Has anyone else tried this and experienced anything similar or contrary?
2. Any ideas how to troubleshoot this?

Message was edited by: irvingpop2:  Correct term is "spanned"