Unsupported method in request dropbox.com

[Gontzal <gontzalp@xxxxxxxxx>]

Hi everybody!!

I get these messages on cache.log:

2011/06/14 10:23:54| clientParseRequestMethod: Unsupported method
attempted by client_ip: This is not a bug. see squid.conf
extension_methods
2011/06/14 10:23:54| clientParseRequestMethod: Unsupported method in
request 'X-Dropbox-Locale: es____'
2011/06/14 10:23:54| clientProcessRequest: Invalid Request

when accessing dropbox:

client_ip - user_name [14/Jun/2011:10:23:54 +0200] "GET
http://notify3.dropbox.com/subscribe? HTTP/1.1" 200 366
TCP_MISS:DEFAULT_PARENT

doing a tcpdump on squid eth and filtering by client ip address I obtain this:

10:23:54.184989 IP (tos 0x0, ttl 64, id 25600, offset 0, flags [DF],
proto TCP (6), length 406)
    proxy-ip.3128 > client_ip.2712: Flags [P.], cksum 0xe043
(incorrect -> 0x3668), seq 1:367, ack 308, win 6432, length 366
10:23:54.188327 IP (tos 0x0, ttl 128, id 59315, offset 0, flags [DF],
proto TCP (6), length 347)
    client_ip.2712 > proxy-ip.3128: Flags [P.], cksum 0xdeb5
(correct), seq 308:615, ack 367, win 65169, length 307
10:23:54.188345 IP (tos 0x0, ttl 64, id 25601, offset 0, flags [DF],
proto TCP (6), length 40)
    proxy-ip.3128 > client_ip.2712: Flags [.], cksum 0x0a1b (correct),
seq 367, ack 615, win 7504, length 0
10:23:54.223297 IP (tos 0x0, ttl 64, id 25602, offset 0, flags [DF],
proto TCP (6), length 1500)
    proxy-ip.3128 > client_ip.2712: Flags [.], cksum 0xe489 (incorrect
-> 0x97d6), seq 367:1827, ack 615, win 7504, length 1460
10:23:54.223331 IP (tos 0x0, ttl 64, id 25603, offset 0, flags [DF],
proto TCP (6), length 326)
    proxy-ip.3128 > client_ip.2712: Flags [P.], cksum 0xdff3
(incorrect -> 0x13cb), seq 1827:2113, ack 615, win 7504, length 286
10:23:54.223756 IP (tos 0x0, ttl 128, id 59316, offset 0, flags [DF],
proto TCP (6), length 40)
    client_ip.2712 > proxy-ip.3128: Flags [.], cksum 0x2099 (correct),
seq 615, ack 2113, win 65535, length 0
10:23:54.226327 IP (tos 0x0, ttl 64, id 25604, offset 0, flags [DF],
proto TCP (6), length 40)
    proxy-ip.3128 > client_ip.2712: Flags [F.], cksum 0x0348
(correct), seq 2113, ack 615, win 7504, length 0
10:23:54.226803 IP (tos 0x0, ttl 128, id 59317, offset 0, flags [DF],
proto TCP (6), length 40)
   client_ip.2712 > proxy-ip.3128: Flags [.], cksum 0x2098 (correct),
seq 615, ack 2114, win 65535, length 0

I don't understand why it says unsupported method when it is just a
GET. Can anyone help me?
I use Version 3.0.STABLE25

thanks a lot!