This is a basic limitation in Crystal, due to the two pass methodology.  Basically, Crystal runs through the data twice in an attempt to calculate everything.  So, in your second formula, it runs through it once to calculate the running total, and a second time to calculate the formula.  It doesn't have a third pass in which to put the formula results in the chart.

Brian's book has some really good information on this limitation, as well as some work-arounds.

The easiest solution is to find some way to consolidate a lot of this work into a single pass.  Is there any way you can incorporate all of that functionality into a single running total?  (Actually, out of curiosity, why are you using running totals to calculate call percentages anyway?)  Can you simply group by your DateTime value, say by day, and use summary values instead of running totals?

How familiar are you with SQL?  If you use the Add Command function to base the report on a SQL command instead of an existing table, you can do some of your functionality there.  That will calculate some of these values before even the first pass.  (Or, even better, you could get your DBA to create a view for you to use.)