From what i read the re-connect charge is to re-instate an acount that was shutoff for non-payment:
Subscriber Agreement
»
www.comcast.com/Corporat ··· ent.htmlSuspension/Disconnect: If you fail to pay the full amount due for any or all of the Service(s) then Comcast, at its sole discretion in accordance with and subject to applicable law, may suspend or disconnect any or all the Service(s) you receive.
g. Reconnection Fees and Related Charges. If you resume Service(s) after any suspension, we may require you to pay a reconnection fee. If you reinstate any or all Service(s) after disconnection, we may require you to pay an installation fee and/or service activation fee. These fees are in addition to all past due charges and other fees. Reconnection of the Service(s) is subject to our credit policies, this Agreement and applicable law