Here's a snippit of perl code:

sub insert_timesheet {
    my $dbh = shift;
    my $entryref = shift;
    my $insertme = join(',', @_);
    my $values_template = '?, ' x scalar(@_);

    chop $values_template;
    chop $values_template; #remove trailing comma

    my $insert = "INSERT INTO timesheet( $insertme ) VALUES ( $values_template );";
    my $sth = $dbh->prepare($insert);
      debug("$insert");
    my @values;
    foreach my $entry (@_){
        push @values, $$entryref{$entry}
    }
      debug("@values");
    my $rv = $sth->execute( @values ) or die $dbh->errstr;
      debug("sql return value: $rv");
    $dbh->disconnect;
}

The value of $insert:

[INSERT INTO timesheet( idx,Start_Time,End_Time,Project,Ticket_Number,Site,Duration,Notes ) VALUES ( ?, ?, ?, ?, ?, ?, ?, ? );]

Here are @values:

[null '1270950742' '1270951642' 'asdf' 'asdf' 'adsf' 15 '']

Here's the schema of 'timesheet' timesheet( idx INTEGER PRIMARY KEY AUTOINCREMENT, Start_Time VARCHAR, End_Time VARCHAR, Duration INTEGER, Project VARCHAR, Ticket_Number VARCHAR, Site VARCHAR, Notes VARCHAR)

Here's how things line up:

----
Insert Statement
Schema
@values
----

idx
idx INTEGER PRIMARY KEY AUTOINCREMENT
null:  # this is not a mismatch, passing null will allow auto-increment.

Start_Time
Start_Time VARCHAR
'1270950742'

End_Time
End_Time VARCHAR
'1270951642'

Project
Project VARCHAR
'asdf'

Ticket_Number
Ticket_Number VARCHAR
'asdf'

Site
Site VARCHAR
'adsf'

Duration
Duration INTEGER
15

Notes
Notes VARCHAR
''

... I can't see the data-type mis-match.