Best way to skip duplicate records when updateng table in vb.net and sql

Hi I have a table made up like
machineID
UserNumber
VMode
IMode
CDateTime
WCode
ValidEntry

there are 3 fields that make the unique key which are
machineID
UserNumber
CDateTime

most times there are about 3000-5000 logs to download and I put these into a table. I used to fill the table first before trying the insert in a try catch block so that is would not add duplicates but takes too long. So then thought lets just get the data and fill a table then update the database. It downloads all the logs in seconds but having trouble when trying to use the tableadapter to save it.

this is what I was using

INSERT INTO CLog
                         (machineID, UserNumber, VMode , IMode , CDateTime, WorkCode, ValidEntry)
SELECT        @machineID AS Expr1, @UserNumber AS Expr2, @VMode AS Expr3, @IMode AS Expr4, @CDateTime AS Expr5, @WCode AS Expr6, @ValidEntry AS Expr8
WHERE        (NOT EXISTS
                             (SELECT        machineID, UserNumber, CDateTime
                               FROM            ClockInLog AS ClockInLog_1
                               WHERE        (machineID= @machineID) AND (UserNumber= @UserNumber) AND (CDateTime= @CDateTime)))

Select allOpen in new window

when the table adapter tries to do the update I get the error
The parameterized query '(@machineIDvarchar(1024),@UserNumber varchar(1024),@VMode' expects the parameter '@machineID, which was not supplied.

I don't get why I am getting this error if I try it in the dataset query editor it works fine.

And does vb.net build a big query and send it in one go or open the connection and loop through the insert statements?