calendar attachments making my agenda bloat

Hi, I am trying to import my calendar into a client system, but I got the feedback that it is too large. It says it has attachments, but I do not use that. I don't attach anything to my appointments.

They say very long hashes like: X-APPLE-OL-DESCRIPTION;TYPE=text/rtf;X-COMPRESSION=X-OL;X-HASH=.......)

Any idea what might cause this and how to fix this without losing my business agenda?

In my iphone I see: App: 2,1MB, docoments and data: 13,5MB, activities 96MB, attachments 0KB