HI danielh68.... from the picture you posted it look like the vertices are not merged or have dupliacted faces. Take a look at that area and just check that all them vertices are really merged.
If they are not merge them, then have your settings to keep faces together this can be found under Polygons> tool options> keep faces together, this will help in the future keeping your extrudes always togther.
Try that... if thats not the case let me know, but from the looks of it its just a vertice problem.
Kurt
I am enough of an artist to draw freely upon my imagination, knowledge is limited, imagination encircles the world. (Albert Einstein)
https://www.artstation.com/kurtb
Last edited by Kurt; 11-09-2003 at 12:37 PM.