Programmes over 30 days old - incorrect warning

[fred.d]

Recently (last couple of months) I've been receiving the warning message 
"You have programmes over 30 days old that should be deleted."

As I've changed my download directory a couple of times over the last 
year I suspected that I'd just forgotten one somewhere.

However I've gone looking and can't find anything.

I thought that using the suggested method of finding them "... --history 
...720..." would help but it simply lists about 4400 of the 5400 items 
that I've downloaded over the years.

...so I went into the download history file which does show the download 
directory for each file. I then tried to cross reference the error list 
of about 4400 with this but of the samples I've looked at so far (about 
50)  none of the downloaded files exist.

Any ideas why I would be getting the warning? Any suggestions for 
further investigation or fix?

It's something I can practically ignore, but I'd like to know why...