"File Error: Data May Be Lost" when file saved on Mac is opened inWindows
 

I have the next problem while working with big report with macroses.
The first time report is opened and executed with special file it with
Excel for Mac 2004. Then saved file is sent to another user who opens
it in Excel 2003 or Excel 2007 for Windows.
In Excel 2003 the "File Error: Data May Be Lost" appears on any
worksheet of report. In Excel 2007 just one time - on the first
worksheet.
So what can lead to this error? If anyone who can help me needs the
example of report I am ready to send it via email.
Thanks in advance.