aggregate functions producing bad data

[Richard Unger]

My query:

SELECT 
	count(id), 
	count( IF(call_end - call_start > 5, id, NULL) ), 
	count( IF(call_end - call_start <= 5, id, NULL) )
FROM 
	t_calllog_calls;

My result:

1994
1956
35

However, 1956 + 35 != 1994.

Running MySQL 3.23.49-nt

Cheers,
Rich