The stored procedure isn't valid in ms sql 2000, because of this line:

where cust_name=@name
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Perhaps you intended this?

select @cust_id = cust_id from x where cust_name=@name
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I tested the perl and SQL you posted with the above modification and experienced the same problem when run from Windows XP using perl 5.8.8, dbd::odbc 1.13. I do not experience this problem on openbsd using perl 5.8.4, dbd::odbc 1.13, and iodbc.

Looking into it further the issue is this line:

$dbh->{odbc_SQL_ROWSET_SIZE} = 2;
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With that line I get the error, without it I don't. Please review DBD::ODBC and check if this option is what you want.

By the way - when testing for the non-existence of a record in sql server you should check 'IS NULL', not compare to an empty string. Like this:

if(@cust_id IS NULL)
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