Edited excel spreadsheet, sent in outlook, saved 4 hrs later.... timestamp is 4 hrs previous - lost changes

[EagleEye(o)]

Hi, I'm using Microsoft Office Excel 2007 on Windows 7 (SP1) with Outlook 2007. I have been editing a spreadsheet throughout the day and saving regularly. At 12:30pm, from w/i Excel, I initiated a send email successfully through outlook. I then proceeded to continue editing the spreadsheet until just before 5pm (saving it periodically). Upon closing it, i went to upload it to a Sharepoint site and found that a copy did not exist saved around 5pm. The latest copy was at 12:28pm (just before I sent it). Can I recover my changes and how?

To net this out:
1. I edited an excel spreadsheet
2. From within excel, selected the send feature (at 12:30pm)
3. I continued to edit (saving periodically)
4. Saved and exited later on (5pm)
5. Found no copy w/latest changes (only a copy at 12:28pm)

Autosave is on (10 min intervals)
I have tried to recover (open/repair and open/restore)
I have looked in TIF (wasn't there)

Any suggestions?