Is is possible that your Ingres table has a column of a custom datatype that SQL Server has no known equivalent for?  Or a size that SQL Server can't handle?

You might try pulling one column, and if it works, add a second then a third, until you determine what the problem column is.  Once you know what the problem column is, you might be able to convert it to a datatype or size that is acceptable.

Lots of luck,

Metra