I been using this quadro 2x for 10 months , and suddenly since 2 days ago it keeps droping the invites from my IP line (Broadvox) so i can not make or accept calls, i go in over the Internet reset the unit and it goes on line again it last for around 4-5 hours and then it happens again , do the reset and back to work any suggestions, on how to fix this, any help would be greatly appreciated .
Also I do not know what this meand in the Systems events , please help

New Thu Mar 31 12:37:40 2011 1 MG rejected by cac System capability exceeded *

This is probably part of the problem but I don't know what it means or how to fix it