Retrieving spreadsheet names with OleDb (performance ?)

[sporadic]

Here's my code (basically straight from msdn help):

System.Data.DataTable schemaTable = connection.GetOleDbSchemaTable(OleDbSchemaGuid.Tables,
new object[] {null, null, null, "TABLE"});

(loop)
string name = schemaTable.Rows["TABLE_NAME"].ToString();

etc.

This is pretty slow on larger files (40mb).
It takes 16 seconds to retrieve the sheet names in an 8 sheet, 40mb XLS file.
Any ideas on how I can speed this up?
Interop is out of the question. That method is way too slow.

Thanks,

Mark