VDIFF - Merge or Souce Compare toggle?

Mongoose

I am trying to utilise the Teamsite visual differences command (iw-cc/command/iw.ccpro.compare_file_source) from within my own cgi window.

I am correctly getting the TS command to show the two files, however as both are in WORKAREAS (and hence writeable), the command opens in "merge" mode. This is NOT what I want - I would like the command to open in Source Compare mode only. I know the command will open in Source Compare mode if one or other of the files is not-writeable, but I believe the command is trying to be too clever!!

Does anyone have an experience with this, and any suggestions on how to force the TS VDiff command to open a window for Source Compare only.

Many thanks
Andy

Stuff :
TS 6.1.0
Solaris