Old templates are still showing up in the template permissions page even though they've been deleted from the server file system.

I had a number of custom templates which I no longer needed plus I had removed all the standard LimeSurvey templates. However they were still showing up in the templates permissions page.
I checked the server file system and confirmed that they had been deleted.
I then went through and checked every survey and change any that listed a deleted template to the correct available template. (All the delete templates still showed up)
I then checked the DB and discovered that they were all listed in the table 'lime_templates'.
After I remove all the entries for the deleted templates from the 'lime_templates' table in the DB they disappeared from the template permissions page.

It seems that LS is not checking the File System to update the 'lime_templates' table.

NOTE:

• All my (custom) templates are unwritable via the web admin.
• All the templates are edited directly on the server via SSH
• Each time I upgrade I start with a fresh install (with old DB) I then delete all the standard templates and copy my custom templates into the templates file from a backup.