AEG probably owns a lot of Fannie, Freddie and other govt. agency bonds. Management insists that they recognized the sub-prime problem years ago and exposure at the sub-prime tranches is minimal and non-material. If AEG owns the bonds that pass through the mortgage payments made by individuals to the bondholder (and I'd guess they do), then there has been a change in the landscape. Previously, mortgage holders were refinancing like crazy. So mortgages were getting paid off - funds that passed straight through to the bondholder. Now there are far fewer refinancings, and far more delinquent homeowners. So the flow of cash to the bondholders has slowed considerably. Velocity of funds is way down. So AEG may be now living on the "runoff of its book" (collecting interest payments on the bonds) rather than having surplus flows of cash from refinancings to re-invest.
The above is not a reason for the hard selling of the pfds. (which I have owned for years), but it is a change in AEG's landscape. I wasn't able to summon up the courage to add to my AEG pfd. holdings this week, but I did add some GEG this morning as it ducked below $23.50