Carrier Heat Pump How long should a dual run capacitor last

[MerciMe]

Our house was built in 2004 and we had lots of problems with our air conditioner from the first time we turned it on and it wouldn't cool. We had multiple freon leaks and even had the coil replaced in our furnace.  We finally decided to change from the installation contractor to another company in 2009 when our a/c again failed.  They had to replace our dual run capacitor and add freon.  

Yesterday in the 100 degree heat, I noticed that the house was warmer than usual.  The air was blowing but was not very cool (probably recirculating the air in the house).  The a/c unit outside was not running.  We turned off the breaker, brushed a little cottonwood fuzz off the unit (wasn't much) and sprayed it with the hose and let it sit.  When we turned it back on, something was running but it didn't sound like it usually does and the fan was not moving.  When the serviceman came out today, he brought a capacitor with him after talking to the oncall tech we called last night.  He had it fixed in about 20 minutes and seemed surprised when I told him we just replaced it two years ago.  Can we expect to have this expense every other year?

[JWWebster]

These newer caps have a diff innards due to the PCB ban. They just do not hold up like the older ones did.

[jumptrout51]

Give us the model number off the compressor.
It is possible too small a capacitor is on the unit.