imenu(/python-mode): clases are there, then not, then there

I am glad to see that in the latest xemacs beta imenu now works fairly well with Python mode. except.... when i first load in a python file, and check IM-Python, the classes and functions are all listed fine, and if i choose an item, the cursor gets shipped to taht location. However ... if i go back now and check IM-Python, the global functions are still listed there, but the classes are gone. if i do rescan, they're back, but every time i hit IM-Python (whether i select anything or not), it has the effect of toggling off the class items which were there after a rescan. i looked through imenu.el but nothing pops out at me as the cause of this toggling behavior. any hints? les schaffer -------------------------------- xemacs: 21.2-b13 python-mode: 3.90 imenu: none listed ( from xemacs-base ) xemacs-base: 1.30 (pkg)