AW: [Zope] Zope and mime types ???

Now if you want to hear something really wierd ...

I've found that if another program on the client machine has the file open at the time you upload it to Zope (e.g. MS Word has it open because you just created it), Zope's copy of the file will get the 'application/octet-stream' type. But, if you close MS Word, then upload it again, this time it will get the correct type 'application/msword'.

I checked this and... yes, it's really weird. So I see no chance to create a product like DocumentLibrary using content/mime types. The only way to get the correct 'mapping' is to use the file extensions ?!? Am I right with that? Please comment. TIA Frank