Sturmey Archer 5-speed hub gears slipping

[sbachrach]

I had a 5-speed Sturmey Archer hub installed on a bike (pictured in avatar) that I'm using as a commuter. I chose this unit because I needed a few gears for hills, but the climbs aren't so long or steep that I'd need a larger gear range. The frame is bamboo, light-weight, and i also wanted to keep the back-end weight as low as possible.
After a week or so of riding (approx 120 miles) the gears started slipping on the hills, at first just slightly, and now progressing in frequency and irksomeness.

1) Is this common?

2) Is this something I can adjust myself (i am reasonably adept mechanically, but major rebuilding of the gear is likely beyond what would be prudent for me or the gear) or should I take it in?

Thanks for any help you're able to provide!

[nfmisso]

1st guess; the shifter cable needs re-adjusting. Most cables stretch a little when new, and the stretch needs to be adjusted out.

[sbachrach]

It was an easy adjustment and is working well. Thanks for the advice!

[trevgbb]

follow the links here and you should find a pdf manual for your hub;
http://www.sturmey-archer.com/products/hubs/cid/4

[sbachrach]

Thanks. I'd found the link online and used the graphics to sort out how to do the adjustment. The hub gear was a bit of a mystery wrapped in an enigma for me, so I'm slowly sorting out how it functions and how I can assist that process.