Read worksheet in excel

[Kaustav]

Hi,

I am facing a peculiar problem with Excel Automation. I have a winform where
in I display some data in a OWC axSpreadsheet. Next I export this data to an
..xls file. When I try to open (through OleDb) and read this file, I get an
error -

"External table is not in the expected format." However, if I have the file
open in Excel, I am able to read it through code.

However the same piece of code works for some files without having them
opened in Excel. What am I missing out here? Please suggest.