The second and more serious problem concerns the shutter. The T90's shutter appears to develop a 'sticky' nature as the camera ages. It is prone to locking up, in which case the camera's LCD displays "EEE" and the message "HELP" appears in the viewfinder display. This is commonly called the "EEE syndrome" among users. The problem is most likely to crop up after the camera has been left unused for some time; thus, the best way to prevent it is regular use of the camera. It does not seem to cause inaccurate shutter speeds before failure. The problem can be corrected by a knowledgeable technician without replacing the shutter mechanism. It is reportedly caused by dirt on the shutter's magnets affecting their performance.
When and if my T90 starts misbehaving it's going in the bin.