The following formula is supposed to return a count of unique values in
column F if 1) column c=c16, and 2) column p=true. It is not returning a
correct value. Any thoughts anybody?

=SUMPRODUCT(--('Jan Database'!$C$2:$C$55200=C16),--('Jan
Database'!$P$2:$P$55200=TRUE),--(('Jan
Database'!$F$2:$F$55200<"")/COUNTIF('Jan Database'!$F$2:$F$55200,'Jan
Database'!$F$2:$F$55200&"")))

Also, why does this darn thing run soooooo sloooooowwwwww? I have a
so-called 'database' filled with about 10,000-15,000 rows of data this
formula is checking.