[squid-users] adobe updates constantly re-downloading

My ~300 users are behind squid-3.2.11. As from 7:00 this morning my 10Mbit/s Internet link is saturated by adobe reader updates:

http://armdl.adobe.com/pub/adobe/reader/win/9.x/9.5.2/misc/AdbeRdrUpd952_all_incr.msp
http://armdl.adobe.com/pub/adobe/reader/win/9.x/9.5.0/en_US/AdbeRdr950_en_US.exe
http://armdl.adobe.com/pub/adobe/reader/win/10.x/10.1.0/en_US/AdbeRdr1010_en_US.msi
http://armdl.adobe.com/pub/adobe/reader/win/9.x/9.5.3/misc/AdbeRdrUpd953_all_incr.msp

I found IPs of update servers, and as a temporary solution I put them into aclnodstip.acl, and modified squid.conf:

acl adobe dst "/usr/local/etc/squid/aclnodstip.acl"
...
http_access deny adobe

This worked well as a temporary solution, as traffic dropped immediately. Next, I followed:

http://wiki.squid-cache.org/SquidFaq/WindowsUpdate

I already had following directives:

range_offset_limit -1
maximum_object_size 8192 MB
quick_abort_min -1

And now I added regex for adobe:
refresh_pattern -i armdl.adobe.com/.*\.(dat|exe|ms[i|p]|upd|dat|zip) 4320 80% 43200 reload-into-ims

Unfortunately, after disabling acl and enabling refresh pattern my link got saturated again.

Any advice how to cache those adobe updates? Or at least make clients download them once, not constantly re-requesting them without ever completing download successfully.

Thank you in advance.

-- 
Marko Cupać