Quark 7 files saved back to 6.5 are MUCH bigger

[karelles]

My client, running Quark 7 on a MacBook Pro, OS X.4, has to save her files back to Quark 6.5. When she does so the files are 15 to 20 times the size of the Quark 7 files. No other changes. She has to do this because her boss has 6.5 and won't upgrade.

Geez, bosses...

Grumbling aside, is there a way to avoid this? Unfortunately, I am an Indesign user so Quark is a bit of a mystery to me.