Indexing problem

I have a very strange behavior while searching files in my computer:
I have a file in my computer with the name 073 issued 11-JAN-2015.pdf

The search filename:*15*.pdf does not return any results while the search filename:*2015*.pdf does.

Does anybody know why?

Thank you

Hi,

Just for more reference on how search works, did you also try searching like Filename:*-2015*.pdf

or just use these, they do work.

Agent Ransack -maybe a bit for powerusers..
Agent Ransack - Free File Searching Utility

Everything - maybe closer to what you are using..
Everything Search Engine