Open Excel 2003 files with Excel 2007 - speed

[ngsebastian]

Hi all,

I'm having a strange problem with Excel 2007, maybe somebody can give
me some help with it.
If I open a xls file that was created using Excel 2003 with Excel 2007
it's very fast. If I try to open a file which is already opened by
Excel 2003 using Excel 2007 it takes forever, maybe 1 min, to get the
"File in Use" message.

Is there a way to speed up this?

Regards,