Mac OS X ipfw traffic shaping

It's related to my common problem with images upload. When I start to upload a new set of pictures the rest of traffic on my isp network connection is being reduced almost to zero.

To decrease the available bandwidth to a flickr website, I've used below commands:

% sudo ipfw pipe 1 config bw 256kbit/s

% sudo ipfw pipe show
00001: 256.000 Kbit/s    0 ms   50 sl. 0 queues (1 buckets) droptail
    mask: 0x00 0x00000000/0x0000 -> 0x00000000/0x0000

% sudo ipfw add pipe 1 dst-ip 87.248.121.213 dst-port 80
33400 pipe 1 ip from any to any dst-ip 87.248.121.213 dst-port 80

% sudo ipfw show                            
33300       0          0 deny icmp from any to me in icmptypes 8
33400    1492    2084081 pipe 1 ip from any to any dst-ip 87.248.121.213 dst-port 80

% sudo ipfw pipe show
00001: 256.000 Kbit/s    0 ms   50 sl. 1 queues (1 buckets) droptail
    mask: 0x00 0x00000000/0x0000 -> 0x00000000/0x0000
BKT Prot ___Source IP/port____ ____Dest. IP/port____ Tot_pkt/bytes Pkt/Byte Drp
  0 tcp    192.168.1.101/57602  87.248.121.213/80     437   611800 46 64400   0

When the job is completed:

% sudo ipfw delete 33400 

OR /if there's no other pipes/

% sudo ipfw pipe flush
Are you sure? [yn] y

Flushed all pipes.