Problems using BEx / Macro

Hi

I have 2 users that expierience strange errors in BEx.

The first user is able to update queries and execute variable selections. If he however tries to change a query the message "Argument not optional" is displayed and nothing happens. Any Idea? Other users have the same authorizations without this error.

The second users Excel session crashes every time he tries to log on BW from Excel. If he however logon from SAP BW TC RRMX there is no problems. Any idea?

Chris