My Canon xti stopped working at my son's graduation. I had a full battery and took a few photos.....then turned it off.....and when I turned it back on again, it was completely dead. Tried several charged batteries and still nothing. Won't even turn on! This is a rather expensive paperweight right now. Is this a defect of Canon xti??

blurring occurs not depending on ISO, i think the lens is the problem. try to clean the lens glass carefully, is there some grease stick on the lens? if not it might be dislocated one of the lens structure.
have you try another lens?

Yes, it could be an issue with the camera or the battery. The easiest way to find out is to try a different battery in the camera. If this works then the most likely culprit is your battery. If this doesn't work then your camera requires service.A good camera store should let you try one of their batteries in your camera.

Camera is dead i think it p fuse gone from md board.
or camera is making battery drain everytime whe you insert battery.
There could be main pcb or md baord or battery box unit.
take it to canon repaire centre and tell them to give you estimate

Your problem may be due to weak/worn out batteries or corrosion on the battery contacts inside the camera which can prevent the full power of the batteries from flowing into the camera. Try this free fix before you do anything else: remove the batteries and wipe the camera contacts firmly with a dry cloth (heavy corrosion may require cleaning with a wire brush, steel wool, or sandpaper). Remove any residue that may have fallen into the battery compartment during cleaning, then wipe both ends of the batteries and place them back in the camera. This cleaning clears the problem about 90% of the time. If it doesn't work for you, your batteries may need to be replaced, or the camera may have a problem that requires professional repair.

Make sure the 420EX is set to E-TTL and set the camera to "P". If is need of more light, increase flash exposure to +1 or 1.5.

I am wondering if you solved your prooblem with your camera, the same thing happened to me and I need it fixed for my daughter's birthday next week! HELP!

CCD sensor is defective and needs replacement. This is a known problem common to various Canon cameras and pertains to a defective batch of CCD sensors Cannon was using. You will get the sensor replaced for free from any authorised Canon service centre. Cheers.

If u had took photo in very low light, pictures will appear blur. Or if you use tele zoom, u need to use tripod to stablize. In normal conditions, you can turn on image stablizer.

This may not be the same as your issue, but our AF stopped working as well. I tried all the recommended fixes - removing the card and battery, recharging the latter, removing the lens and cleaning the contacts, etc. None of those things worked. However, I then switched to MF, requiring me to turn the barrel, and I realized it was stuck and just needed a little force to get unstuck. Might have been the humidity. Anyway, our problem was solved - AF was back to normal after that.

This definitely looks like an issue with the Camera. I suggest contacting the Camera Tech Support immediately and request them to send the Camera to the service center. There are more Canon Rebel XTi owners, including me have experienced no-power issues albeit not exactly similar. More discussed here: http://www.fixya.com/support/t270989-xti_wont_power_up

I also do not think that any user action can fix this issue. Just call the tech support, and they may say that they never heard of this issue, please point them to this thread. Good luck.