I go on an ad update every 6 months ago, sometimes i come across sites i listed on 2 years back but come to find I have no ad. These sites arn't like 30 days only kind of sites, they're just free directories. Anyone else find this? As if we don't spend hours listing as it is

Yes, it's always good to update even the free directories.  Every couple of months at least.  Directories will do a clean out every so often for many girl don't stay in the business.

When you are listing on these directories always take a note of their name, your username and password for its easy to forget if you don't use daily.

I check all my directory listings and log in to all directories every month or two to ensure they are up to date, showing up on the correct parts of the directory and the log in still works etc. Many will remove ads that appear inactive, though far too many sites have clearly no longer current ads up.