2001 "Cylinder 1 Misfire" (again), possible fuel flow issues.

This is a bit of a mystery to me, I'm hoping someone can shed some light on it.

About 4 - 6 months ago, I had a "service engine soon" light, the code was "Cylinder 1 Misfire".  I changed the plugs and wires, and everything was fine.

About 6 weeks ago, the car started having problems accelerating (no "service engine soon" light).  The RPMs would drop slightly when the problem would occur.  I had the fuel injectors cleaned (the fuel filter is only about 2 years old), and this resulted in a big improvement in acceleration.  

About a week ago, the acceleration problem returned. Then the car started running bad constantly, and I finally had another "service engine soon" light. The code reads as "Cylinder 1 Misfire" again.  

I'm confused as to why I would have this identical problem.  An issue with the cylinder itself seems very unlikely: The car has only 25,000 miles on it, it has  never overheated, has had its oil and filter changed every 3000 miles, and is not burning blue/white smoke.    

So, what could be causing this? Should I be looking at the computer brain/chip? Given that the fuel injector cleaning helped things temporarily, should I be looking for a fuel flow issue? Is there a fuel injector that only effects Cylinder 1?

I'd appreciate any insight. Thanks  

Sometimes parts just go bad - replace the plug and if it happens again you may want to confirm that cyl's injector is working properly.  To my knowledge, after the TB injection sytems mostly went away back in the 90's, all engines today are pretty much direct injection (each cyl has its own)