I was working on a spreadsheet and as I was saving, another colleague to to open it. They couldn't get into it and then when I tried I got the following dialogue boxes:

'####.xls' cannot be accessed. The file may be read-only, or you may be trying to access a read-only location. Or, the server the document is stored on may not be responding.

Retry Cancel
When I click retry nothing happens so I click cancel and:

Excel found unreadable content in '####.xls'. Do you want to recover the contents of the workbook? If you trust the source of this workbook, click Yes.

Yes No
So I click Yes:

Unable to read file

Ok
Click OK and nothing happens. Now I was in the spreadsheet five minutes before this happened. It's not read only and the server was fine.

Can anyone shed any light on this for me please. It has a whole year's worth of data in and I need August's data for a report due Thursday. I can get a back up from our IT department from the server but it could take 5-7 days.