I have not used 2 circulars, but on regular DP needles it helps if you pull the first AND also the second stitches very tight.

Ditto

Deb, when you cast on, use the dbl points until you have joined and knitted your first round. That seems to help me. Once you have it that far, go ahead and switch to the 2 circulars. See if that helps.

Tami