itable cant be renamed

Hi all - I'm probably missing something very obvious - but i cant rename my itable objects.

I have a patcher with 2 itables, the first is named tab1 (copied from a tutorial patcher) and the second wont let me rename it - i can change the scripting name, long name and short name - but not the 'table name' which the expr object uses to identify it (i think!)

The table name feild in the inspector is blank and whatever i type in there vanishes as soon as i click away

Any ideas?

thanks in advance

Andy