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.
Don't bin it! Remove the lens, gently raise the mirror up against the top of the shutter box, than smack that sucker down on your carpeted floor! Once, twice, then try to fire it -- it may make an exposure, then lock up and give you EEE again. Smack it on the floor again, and fire it off again. I usually find that this simple "repair" gets it going again, then I put it on continuous and blast off 10 or 20 exposures (not with film, of course). All I have to do from then on is pick up the body weekly and run off a bunch of exposure, and it's a happy camera. It's only when I forget to give it the attention it craves that it starts to yell EEEE at me!