Monitoring network interface

[MichaelF]

Hello!
Please tell me what am I doing wrong trying to monitor the switch port (40) my computer is connected to - here are my steps:

1) Create the snmp item for the incoming traffic (1.3.6.1.2.1.2.2.1.10.40):

ifInOctets

1.3.6.1.2.1.2.2.1.10

The total number of octets received on the interface, including framing characters.

2) Create the snmp item for the outgoing traffic (1.3.6.1.2.1.2.2.1.16.40):

ifOutOctets

1.3.6.1.2.1.2.2.1.16

The total number of octets transmitted out of the interface, including framing characters.

Test: I download a file to my computer and expect to see the first item climbing up but instead it is the second one which starts growing - as if I'm uploading this file, not Downloading - please see the attachments.

Thank you in advance,
Michael