I don't see any problems with this portfolio. The total exposure to B of A / Merrill Lynch is a little more concentrated then I would like, but I think the preferred dividends are secure. So if most, if not all, of these preferred dividends are secure, this fund is a screaming buy.
If you are looking at the portfolio listed on Yahoo, it is quite old. If you go on the Invesco website and check the PGF portfolio as of 9/15, the fund had no exposeure to Lehman. There is exposure to B of A, CitiGroup, MetLife and others who are in the news today, but I think the current price of PGF is way oversold. Worst case, I suppose one (or even several) of the holdings may suspend their dividend until this blows over, but I have to think PGF is a good investment at these levels. Am I missing something?