UPDATE Trigger Not Working Properly

We've altered an UPDATE trigger - now it doesn't work properly. When updating a record (via a web application) by clearing the value for a particlar column, we get error:

UPDATE failed because the following SET options have incorrect settings: 'QUOTED_IDENTIFIER'.

Code = 800a0c93
Source = ADODB.Recordset
Description = Operation is not allowed in this context.

What the trigger does is prevent a zero-length string from being inserted into the database, which violates a check constraint, and instead inserts NULL. The web app - whose code we cannot modify - apparently does this. This was working fine, until we altered the trigger to add an additional column for update. Our SQL developer person has left, so us less knowledgable (about SQL) folks are trying to pick up the slack.

trigger code:

SET QUOTED_IDENTIFIER OFF
GO
SET ANSI_NULLS ON
GO




ALTER TRIGGER trigViaNetCardholderUpdateEmptyStrings
ON viewViaNetCardholder
INSTEAD OF UPDATE AS
UPDATE tblIDCross
SET
tblIDCross.chUSCId = CASE WHEN ins.chUSCId = '' THEN NULL ELSE ins.chUSCId END,
tblIDCross.chNineDigit = CASE WHEN ins.chNineDigit = '' THEN NULL ELSE ins.chNineDigit END,
tblIDCross.chPID = CASE WHEN ins.chPID = '' THEN NULL ELSE ins.chPID END,
tblIDCross.chEmployeeId = CASE WHEN ins.chEmployeeId = '' THEN NULL ELSE ins.chEmployeeId END,
tblIDCross.chAIMSNumber = CASE WHEN ins.chAIMSNumber = '' THEN NULL ELSE ins.chAIMSNumber END,
tblIDCross.intCustomerType = ins.intCustomerType
FROM INSERTED ins
WHERE tblIDCross.intUSCardId = ins.intUSCardId




GO
SET QUOTED_IDENTIFIER OFF
GO
SET ANSI_NULLS ON
GO

Please help...