I have had this item for several years now now and have never ever had an issue with it.  It takes a bit to learn but once you do, it will do anything you want it to do.  It has served me well, so far so good...but I will keep my fingers crossed!  I actually took a calculator class so that I could get the most out of my calculator.  I needed to use it for all of the math classes that I needed to take for college.

The only problem I have had so far is that I have had to replace the battery one time.