I would like to try to recreate these problems but I need more information.
What type of mobile device (or devices) is (are) being used?
What operating systems are in use?
For the excel documents are they xls or xlsx file formats?
For the SAVE issue, does this happen only for excel files or for other file types too? (and for which other file types?)
Do your file names have spaces, caps or special characters?
Any additional detail you can supply would be a big help.