Front derailleur problems

[DrCycle]

I have a problem with my girlfriend's MTB Raleigh AT20 front mech. It is very difficult to shift up from 1 to 2 and then 2 to 3. I have raised the chain stay cage to 2 mm from the biggest chain ring, replaced the chain (which was worn) and indexed the gears. However, you have to overshift to get it into gear. My local cycle shop has suggested replacing the gear cables (inner and outer). However, the bike was only bought in December 2008.
Any suggestions?
Dr Cycle, England, UK

[DaveM]

If there are any sharp kinks in the cables, that could make the shifting tough and need replacement. One question is if the shifting has gotten noticeably worse, or if you always had to overshift. If it hasn't changed much, it could just be lower end shifters that don't work great. But if it used to be good, then something has changed.
Make sure outside of front derail is parallel to the chainrings. Inspect cable for kinks or corrosion and drip a little chain lube on the cables where they go into the outer.