Say I'm editing foo.install.inc and I type h_install. I get something like this:
function hook_foo.install_install() {
}
The Filename() function in snipMate only removes the first "extension". So the basename for foo.install.inc is foo.install.
I fixed this in my fork and issued a pull request. Basically, I declared a new function in plugin/snipMate_drupal.vim that trims off up to two extensions. This function is called DrupalFilename(). I then replaced all instances of Filename() with DrupalFilename().