we have a strange situation that excel file wouldn't save properly on our SharePoint 2010(just upgrade last month from 2007) . and there is no error message show up.
1. if we open a excel files from SharePoint in "read only" mode, then click the edit button to modify, it will not save.
2. open a excel file directly from a link, for example http://sharepoint/department/docs/text.xlsx, it will not save.
However, if the excel file is opened from sharepoint and opened in edit mode, it will save without any problem.
I tried Word and PowerPoint files, they both can save OK on any of the situations above.
I also see that the save icon on Word and PowerPoint both come with a little green sync icon, but the excel doesn;t have one. I am not sure if this is the issue.