Why wouldn't a .install file be loaded? My latest module does not seem to be loading .install when enabled.  Here's the rundown:

I have a .module file implementing hook_menu() and hook_views_data().

Both appear to work fine, after enabling the module: navigating to the menu path works as expected and my new views base type is present.

I have a .install file implementing hook_install() hook_uninstall() and hook_schema() 

None of the functions in the install file appear to run.  The new tables are not present after enabling  and there are no errors logged.

If I manually call the functions in the .install file with devel THEN I get an undefined error.  I can only assume that the install file is not being loaded.

Running the .install file through the command line PHP interpreter doesn't bring up any syntactic errors.  

I'm at a loss to explain why the file is not loaded into scope when the module is enabled.  

I'd appreciate any assistance.
Turns out it was an error in hook schema() unfortunately the function failed more or less silently. For example :

'description' =&gt; array(
                'type' =&gt; 'varchar',
                'size' =&gt; 'normal',
                'not null' =&gt; TRUE,
                'description' =&gt; 'Description of vaule type.',
        ),


Failed.

'description' =&gt; array(
                'type' =&gt; 'varchar',
                'size' =&gt; 'normal',
                'length' =&gt; 255, 
                'not null' =&gt; TRUE, 
                'default' =&gt; '',
                'description' =&gt; 'Description of vaule type.',
        ),


Worked.

The problem was exacerbated by my mistakenly assumed notion that disabling and re-enabling a module would trigger the install, rather then the removal of the module from the system table.

Thanks again to everyone who provided feedback.