Issue during table creation at runtime

Hi
I'm adding rows and data to exisitng table from code behind [vb.net]; objects properties are assigned runtime and ensured it is unique for each entry. Issue I'm facing is when a I try to add 10 th row to the table, application errors out
But where as when i try to add only 9 rows or lesser application is running without any issues. This is very weird, could you please let me know what would be issue here