Mine always had cracks on the teeth of the belt. Kinda hard to see with the timing belt still on the car but if the belt were to be flipped over and the teeth pushed out the cracks could be clearly seen. Many timing belt failures are due to the tensioner actually going bad and causing the timing to jump. Right before this happens the tensioner starts with a clicking or tapping noise during cold start ups, but not always does this happen. It can happen randomly. Some of the timing belts strip teeth, due to the cracks next to the teeth. My advice is inspect the belt closely. But plan on doing a timing belt job ASAP with OEM Mitsubishi parts. Do not use a parts store hydraulic tensioner. Do not cheap out on the main parts that keep your engine running. Any failure in the timing components can be VERY costly.
Edit: Just seen you have an N/T. The hydraulic tensioners on those don't seem to fail quite as often but there are a few people that swap over to a mechanical tensioner.