Upgrading to testing with broken potato dselect?

[Martin Edward John Waller <martin.waller@flomerics.co.uk>]

Hello,

I have potato with XFree 4.1 installed.  But
whenever I run dselect now, it insists on removing

XFree4.1 (which I need for my video card).
If i change my sources.list to point to testing
and do

apt-get update --fix-broken

will that upgrade my system cleanly and let me
keep Xfree4.1?

Or is there more to it than that?

Ta,

Martin