Duplicate artists appearing on my ipod

You need to make sure the artist name is spelt in an identical manner on every track. Even an extra space at the end of the name that you might not notice can make a difference. Try this even if everything looks the same. Sort your iTunes library by artist to bring your tracks together. Click on the first track by your artist, hold down the shift key and click on the last track in the list, this will highlight all in between. Right click on the list and choose Get Info, you get a dialogue box asking if you want to update multiple items, click Yes and then the Info tab. Overtype the artist name then click ok and this will ensure the whole selection is identical. Once you've done this connect your iPod, if you are updating automatically it will pick up the changes.

Just to double check, go into iTunes, highlight that artist and/or songs, right click on them and select "get info".

This brings up the multiple song info window. If you see the "artist" field is left blank, then there is a discrepancy with that name.

If the above is not the issue, try this also. Highlight all the songs for that artist, right click on them and select "apply sort field/same artist".

See if that works.