Re-creating a file in SharePoint

I have developed a sharepoint application using object model. It reads the contents of the file using SPFile.OpenBinary() object and saves the contents of the file in the local disk. When I try to create the same file again with the saved content, the file size differs. And t开发者_JAVA技巧his happens only for office application files (.doc, .xls and .ppt files). So does sharepoint add metadata to files when we upload them? If so is there any way to distinguish metadata added by sharepoint?

Prabhu,

please check your upload/download algorithms; Sharepoint does not add metadata to your file content, so something is wrong.

If you could post your code, we can help trying to find your mistake.