Delay pool

Hello All!

I want to limit bandwidth not for client but for some file types.
>From squid.conf :

acl Waves urlpath_regex "/usr/local/squid/etc/waves"
delay_pools 1
delay_class 1 1
delay_access 1 allow Waves
delay_access 1 deny all
delay_parameters 1 1000/1000

Content of /usr/local/squid/etc/waves is:
\.mp2$
\.mp3$
\.mpg$
\.mov$
\.wav$
\.rar$
\.arj$
\.rpm$
\.avi$
\.rmi$
\.ra$
\.exe$
\.com$
\.tga$
\.cab$
\.qt$
\.omf$
\.pdf$
\.zip$

Not work. Why ? I'm so dummy or not ?

-- 
Best, Serg <serg@tv2.tomsk.su>