wrong Modified date saving Visio drawings

[Guy]

Hi,

I recently upgraded from Visio 2002 to Visio 2003.
When I now change older Visio drawings that I have created
in VISIO 2002 and I want to save them, I get 3 options.
1) saving in current version
2) saving in Visio 2002 format
3) cancel

When I save in Visio 2002 format, the modified date change
to the current date. But when I am saving in "current
version", the modified date didn't change!
Why?
Are there any customisations/options I missed?