Slow Query

Hi,

I am running a query that I feel shouldn't be taking as long as it does to
execute. The query is as follows;

SELECT traffic.trafficin.bytes_in as bytes_in,
round() as serverallkbytes_in,
cache.server.tstamp as tstamp FRM traffic.trafficin LEFT JIN cache.server
N(from_unixtime(traffic.trafficin.time,"%Y %M %d %H
%i")=date_format(cache.server.tstamp,"%Y %M %d %H %i")) WHERE (
traffic.trafficin.name="em0" AND cache.server.tstamp 0) AND
((date_format(cache.server.tstamp,'%Y-%m-%d') BETWEEN "2008-05-31" AND
"2008-06-10" ))

Here's the output from the explain;


| id | select_type | table | type | possible_keys | key |
key_len | ref | rows | Extra |

| 1 | SIMPLE | server | range | PRIMARY | PRIMARY | 4
| NULL | 3952 | Using where |
| 1 | SIMPLE | trafficin | ref | namekey,nameindex | namekey |
30 | const | 25867 | Using where |


The strange thing is, when I remove the date range the query executes in an
acceptable time. Can anyone maybe point me in the right direction?

Thanks,
Darryl