[zack251]

I found out that Office can't edit older version of Office documents as well as RTF format. Is this correct? and Why?

[blevok]

i also made a similar discovery just yesterday. my boss created a spreadsheet on google docs, then saved it as an xls, uploaded it to my skydrive. i accessed it on my phone all day, adding lots of information. then i went to a pc and looked at the file in the office web app. after that i cant edit the file anymore. i notice that the file now ends with .xlsx
i opened the file in desktop excel, and re saved it in a half dozen formats including older versions of xls, and still couldn't edit any of them. i feel like it might have to do with unsupported characters or formatting being somehow added, maybe by the web app.

[mitixx]

Yes, same happened to me a while back.
I was proud about my new phone -2days of use-, with the Office pre-installed. So when I received an email with an .xls file attached I thought it would be possible to edit it on the go...
I find it quite bad, since I know many people who just keep using the older formats (the ones without the "x") because not everyone has updated their Office suite.