Android: Simple GridView that displays text in the grids
I am not sure what could be causing your problem. I followed the step by step instructions on the page that you linked to to set up "Hello, GridView", and used your code and was able to see the text.
The only things I changed was rather than creating a class for ImageAdapter I used your MyAdapter. In the activity HelloGridView.java onCreate I used "MyAdapter" rather than "ImageAdapter". I didn't change the layout at all.
Here is a Screenshot of what I get when running your code.