Excel 2010 create 0 size .xlk file in save as when i save it with different name.

[Vagelisr]

Hi to all
I'm facing a strange issue.
In a specific excel file ONLY!!!!
When i save as with a different name always they create a XLK file with 0 size.
When i create a new xlsx file even if i go to Save as -> Tools -> General Options -> and check "Always create backup" when i press Save as with a different name they DID NOT create xlk file where is the normal.
Only the specific file in Save as always create the xlk file with 0 size.
Does anyone have an idea why this happens???
Thanks and regards...