i also believe its KPCC calling during pledge week or about or sustaining contributions... but the worst part is that after the 10th time I finally had a chance to pick up and i got nothing but static silence before that cal cut off. And, not due to my reception either.
I have received 4 of these calls over the last few days, no message left. It makes sense that it is KPCC as I am a renewing member and they are having a spring pledge drive.