Error 0x81840021 and Error 0x8183007a

[netdoodle]

Using Version 4.1.0. with ip obtained from local DLINK DL-604 router every 2 minutes. I get the above errors on the average of about 2-3 times a day otherwise the system seems to be stable. The router log does not show any disconnects. Is this something I should be concerned about and what could be causing it?