What crankset do you have on the bike?
If it's a Shimano with external bearings, there are spacers that set the chainline. Make sure these are correct, and that the RH crank is not too far out.
I assume you have wound the limit screw out far enough to allow the cage to move over.
I've been running Shimano 48-36-26 cranks with Tiagra front derailleurs on 2 different bikes for a while.
I did find that I needed to rotate the front derailleur mount at one stage to get good gear shifts. I suspect it was bumped out of alignment at some stage.
On my wife's bike, I had to adjust the positioning vertically after I changed the crank size.
As usual, Sheldon Brown (RIP) has some words of wisdom here
http://sheldonbrown.com/derailer-adjustment.htmlHe includes the warning:
"Front derailer adjustment is not an exact science. It requires a good eye and a bit of patience to get it right."
I couldn't agree more!
If you have a good bike shop near you, it would be worth asking for help.
Trying to get the front derailleur working right can be a very frustrating experience, particularly with a triple crankset, but changing to a different device will not necessarily help. For what it's worth, I've had bikes with a range of different Shimano front derailleurs, (Alivio, Deore, Tiagra, 105 double) and have always managed to get them working eventually.
Good luck!
