unable to send documents via hotmail from my mac book air

Hello,
Can anybody help please? Im finding it impossible to send documents from my macbook air as attachments via hotmail. Keeps coming back as attachment ID has bad format!!!
I downloaded openoffice.org software the other day but hasn't made any difference.
***??
Very frustrated and confused mac user (

Are you trying from the mail client or from the hotmail interface in a web browser?

What type of file?

Also, are you adding (or making it a default to add) the extension (ie .doc) to the filename?