My wife was having problems stapling today so I looked inside this one and found that the staple had fallen over inside the stapler. So, instead of the staples forming the upside down "U", all ready for the teeth to punch into the paper being stapled, the staples were positioned with the teeth to the front and the base of the "U" facing the springloaded rear of the stapler.
This is just poor design as some misguided engineer tried to cut costs. All other staplers I've seen have some sort of platform down the middle of the staple feed chamber. This allows the base of the "U" to rest supported on the platform and not depend on standing upright on their feet. Getting rid of that platform means that the staples can fall over when the stapler is loaded or if the spring's tension is off.
Or perhaps it isn't poor design -- A little experimentation showed that the stapler has one feature sure to please a company exec, provided it's the exec of Swingline: It's nearly impossible to load small quantities of staples into this design. With nothing to support them, they just fall over and slide underneath the other staples.