You can't use 'Pass 2' formulas in cross-tabs or in other summary formulas. This is because the summaries are all calculated in the second pass of report generation and it can't guarantee that the formula results will be available. You can only use 'Pass 1' formulas (simple formulas that only do basic calculations) as a basis for other summary calculations.

I cover the three-pass report processing model and how it effects your formulas in my Encyclopedia book. You can find out more about my books at Amazon.com or reading the Crystal Reports eBooks online.