In article <4v13vg$3lh@newsstand.cit.cornell.edu>, d_ruether@hotmail.com says...
[....]
>Either the ASA setting is higher than 400, or the shoe cover is not
>rotated closed (necessary for the ASA "feeler" to engage the ASA tab
>on the camera).

Ooopssss....! I did what I holler (silently! ;-) at others for doing
(it was VERY late.....): I didn't read all the related posts before
answering.... Tsk!, tsk! I think others got it right: probably a dirty
TTL contact was the culprit.
Hope This Helps