I had similar symptoms ... a simple install file that wouldn't create a table.
However, I got it to work by going into the Drupal system table and deleting the record for my module.
Then the next time that I enabled my module, Drupal freshly discovered it and ran the .install file to successfully create the table.
Summary. When you have a module already in use (and so it appears in the system table),
and *then* as a developer you create its .install file,
it doesn't look like a *new* installation to Drupal (since the module name was already in the system table), so hook_install never gets called.
Trick for schema's that won't install. If you have a custom module that you _had_ installed before making a .install file and including a schema, you need to: (1) Disable your module (2) Uninstall your module (3) Delete your module's row in the 'system' table in your Drupal database. Then you can re-introduce your module, and all its files will be recognized.