Here are the facts that I see looking into this:
GUID: 712619b7
Last seen using name BY0: Jun 08, 2009 at 3:55 pm
IP seen while using that name: 90.219.184.114 (origin UK)
GUID: 8d68f6a4
Last seen using name BY0: Aug 10, 2009 at 3:11 pm
IP seen while using that name: 85.226.150.136 (origin sweden)
GUID: b09be569
Seen: Aug 10, 2009 at 3:19 pm
IP: 173.30.30.208 (origin US)
Seen: Jun 08, 2009 at 2:09 pm
IP: 24.13.104.246 (origin US)
Based on this information, it is highly unlikely that the GUID/ban you are being accused of is actually you. The GUID 1d386780149dd4e434d60e69b209e022 is a leaked key and was seen with the name BY0 using an IP from sweden as above. Definitely not him.
The GUIDs are not 'linked' to you at all. They do however show up if you do a search of your name. Based on the IP you are posting from, I only found the one GUID (b09be569) and could not get to any of the others through linked GUIDs (based on being seen on the same IP at one time or another).