I went to the Brentwood Coronation Event at King George's Fields Bank Holiday Monday using a black AE-1 and finished a Konica VX 200 on Mayor arriving by Horse Carriage , Lord Lieutenant of Essex etc then re-loaded a FUJI SUPERIA 400 -- well I processed the KONICA in fresh C41 and film was blank except for the small fogged leader -- so I CUT the Fuji Superia and processed and majority was BLANK except for 5 frames --- I checked Camera -- looked through back and SHUTTER was NOT OPENING !! DISASTER !! Lost all the VIP snaps, the Bands etc etc -- then on trying shutter speeds put it on 'B' and it worked -- then tried other speeds and shutter worked -- so What went WRONG !! Any IDEAS !! ?? I took off Base-plate and had look - the magnets seemed to be clean enough --