Ok I changed it to this for testing:

Dim myCmd As New System.Data.OleDb.OleDbCommand("CREATE TABLE test (filename varchar(100) Unique)", myConn)

However it errors when I try to raise the length of the field above 100, whereas in foxpro I could take it to 240. Is this a limitation of the driver Im using? If so, what other tables could I use to get to 240 with an index?