I have seen several problems logged on this and no solutions.The Edit In place functionality works great for us most of the time, but occasionally we get problems like this.
Here is what I observed on one users machine last week. ( I have seen it happen on others ).
I performed in the region of 40 tests on this machine, all with varying results.
On an Excel attachment, Using either right click and edit, or double click and edit from read mode ( and the Notes document being automatically placed into edit mode ), or from edit mode.
I made changes to the Spreadsheet, then either closed Excel and followed the prompt to Save, or Saved manually ( sometimes 3 or 4 times ), and closed Excel. I then manually saved the Notes Document, sometimes once, sometimes several times.
35 out of 40 of the tests my changes were lost.
3 times my changes were saved.
On one delightful occasion, the ORIGINAL changes that the user had LOST when they had first updated the file came back, stayed for 2 saves, and then disappeared again, this time for good, to be replaced again by my changes.
These first changes could not have been in the file all along, as the Notes document had been forwarded to someone else, who had complained that the file was empty, and sent it back.
That was when I got involved.
Excel was fully closed between each launch.
There are no replication save conflicts.
This sounds like a possible caching issue to me.