Does anybody know of risks regarding the POWERSHARES fixed income ETFs and their failure due to lack of volume? I read an article about how some other ETFs have failed and been shut down due to lack of $$$ volume. Some of the POWERSHARES fixed income ETFs have relatively low (but consistent) volume....

I have NOT seen anything indicating that any of POWERSHARES' fixed income ETFs are at risk of failing, but was just wondering because I find the following funds to be particularly attractive (and I am thinking of investing in these products):

PZA
PHB
PCY
PGX
PGF
PEY

Any comments would be appreciated