Are you importing the data table from external to source? The QTP data table has an xls extension but is not MS Excel and will not read several custom features of MS Excel. Recommend cleaning the datatable.

If you are importing data please review the following HP documents
Document ID: KM781683
Title: Is the QuickTest Professional (QTP) DataTable control based on Microsoft Excel

Document ID: KM1210912
Title: DataTable.Export (or ExportSheet) returns error: General Run Error/Unspecified Error

Document ID: KM324314
Title: How to clean up all Excel formatting in XLS file using Microsoft Excel

Document ID: KM883046
Title: How to clean up all Excel formatting from XLS file using QuickTest Professional (QTP)

I am unbale to see the hp documents you mentioned above. Can you please guide me how can i see those documents. It would be great if you can share the document copy.