Sorry for my first post to be a bug report, but I searched and couldn't find this in the known issues list.
When I raised my Sailing skill to 10, the Fencing skill button greyed out rather than the Sailing one (I had two skill points to spend at the time, so it was particularly notable). As an experiment, I then added an 11th point to Sailing. My Fencing skill was 5 at the time.
In case it's relevant, I have a Motorola Milestone (aka Droid), and I was playing a test game (Fountain of Life, Apprentice difficulty).
Another thing which perhaps doesn't qualify as a bug, but which is slightly annoying, is when you're creating a New Pirate: if I edit the pirate's or ship's name before assigning my skills, each time I hit a + or - skill button, the screen scrolls back to the top (or rather, back to the textbox with the focus), requiring me to manually scroll back down to modify the next skill.