Leave old in mass edit doesn't work

[Andrew]

In mass edit I see two problems with group editing

1. The 'leave old' option appears not to work.  By default it is ticked and I'm assuming that this is meant to mean that existing groups will be left as is - but if I tick, say, one other group and then update, only the newly ticked group remains on the trade - the old groups are removed.
2. I can't untick 'leave old' (I see this was raised before but it's here for completeness)

I'm using TP 1.0.2 build 18 and Firefox 3.0.13

[Shorr Kan]

fixed