I have never experienced this problem. Are you sure you call:
beginEdit(id);
then
performEdit(id);
performEdit(id);
performEdit(id);
...
then
endEdit(id);
I have encapsulated this sequence in a Editor concept, so that I don’t really have to think about it (beginEdit is done in constructor and endEdit in destructor).
Although now that I look at the code, it seems I also call setParamNormalized (see setValue method) in addition to performEdit.
Yan