Nope. The volcano didn't erupt at all at that time. I didn't get the message. The only mesage is that Senate suddenly allied with Carthage. The funny thing is that usually if your allies make aliiance with your enemy, automatically you become neutral with that faction and siege automatically lifted but this things didn't happen.

The siege is still on at that time, only my units are halves.. ouch..

Bug or what... anyway . diplomatically speaking if happen in real situation, maybe some of my 'soldiers' who loyalty more towards Rome (Senate) and so disband themselves rather that continue making war with Senate's ally. .