When calculating the accumulated total DAP and RP doses over x weeks for the first time after upgrading to 0.9.0b3 I received an error to say that the calculation had failed. Viewing the rf summary pages showed that values had been calculated. However, some rf summary pages failed with an error saying that sigdig required a float. Investigation showed that some values being passed to sigdig were empty strings.
I need to further investigate the original error that occurred when I first calculated the accum doses (this message has not reappeared since).