Error when right clicking and selecting properties

I am using BEx 3.5 (latest patch), Excel 2010 and Windows 7.

When I use right click to select any Property (whether overall query or idndividual object), I get an Excel error 'Type Mismatch'.

The other object right click functionality e.g. Select Filer Value or Drilldown still works !

After this 'Type Mismatch' error, any further right clicks will only brings up the standard Excel menu and not the BEx menu.

I suspect this is a VBA error, any idea what is casuing it ?

Thanks

Lindsay Kirby