Sorry for the aggravation, Allen....

I think a few issues you might have experienced are because of the size of your image (larger image will require different settings for some of the work) and the age of the tutorial (stuff has moved about and changed in Gimp).

The people here are usually good at assisting, as do I when I can, so posting a WIP (Work in Progress) along with HELP type requests usually gets you somewhere.

There are numerous other tutorial that can be "plugged in" to replace some of the steps that typically give better results that my techniques. Here are a few:

My random coastlines: http://www.cartographersguild.com/showthread.php?t=875
Karro's jitter method: http://www.cartographersguild.com/showthread.php?3216
OldGuy's photoshop method that also works in gimp: http://www.cartographersguild.com/showthread.php?9056
A thread on making rough walls that can port well to landmasses: http://www.cartographersguild.com/showthread.php?4140

Better/Alternate/Easier Mountains:
http://www.cartographersguild.com/showthread.php?2931
http://www.cartographersguild.com/showthread.php?7961
http://www.cartographersguild.com/showthread.php?4335
http://www.cartographersguild.com/showthread.php?5009
http://www.cartographersguild.com/showthread.php?2825
http://www.cartographersguild.com/showthread.php?8213

More fuel for the fire

-Rob A>