Check the tripod bush to see if you have pushed the top off the socket into the mechanism.
This can cause 'odd jamming' problems depending on where it may have fallen

By Loft Photography on Thursday, June 05, 2003 - 05:52 pm:

The damnedest thing happened recently. At a shoot one of my RZ�s stopped working (thank god for back-ups) and after taking it apart later and finding nothing obviously wrong I discovered it functioned only in one of three ways:
1)in full manual mode(no battery)
2)upside-down
3)with the bellows fully extended.
In any other position the shutter opens (I don�t think anywhere near the set exposure) and then not until 90sec later does it reset so you can move the wind lever.
I am at a complete loss. I consider myself pretty handy and would rather fix it myself if I could. Really any info or suggestions anyone can come up with would be greatly appreciated. Thankx.
-matt