Falling hit ratios?

Problem:
System has been working GREAT for several months, moving from 1.x to 2.x.
Machine talks to two parents on two different pipes, using "round-robin".
Recently compiled for "delay pools" and "cache digest". Over the weekend
the "hit ratio" started falling from 45% avg down to 12%??? Thinking the
store.log was corrupt, I removed and rebuilt. No help. Logging shows
misses?? Why am I getting such high miss ratios? This wasn't happening 1
week ago.

System:
P2-300/256M/RedHat 5.1/2.0RELEASE/IPFW/ Cisco 2514 route-map

Log:
908807475.161 52 204.203.237.144 TCP_MISS/302 165 GET
http://www.cbvcp.com/ - DIRECT/www.cbvcp.com -
908807475.756 418 204.203.237.144 TCP_MISS/200 24884 GET
http://metro.cbvcp.com/cbvcp/ - DIRECT/metro.cbvcp.com text/html
908807476.644 70 204.203.237.144 TCP_MISS/304 119 GET
http://metro.cbvcp.com/cbvcp/graphics/lighoff.gif - DIRECT/metro.cbvcp.com -
908807476.715 32 204.203.237.144 TCP_MISS/304 119 GET
http://metro.cbvcp.com/cbvcp/graphics/newsico.gif - DIRECT/metro.cbvcp.com -
908807477.265 143 204.203.237.144 TCP_MISS/304 119 GET
http://metro.cbvcp.com/cbvcp/graphics/entertainico.gif -
DIRECT/metro.cbvcp.com

908807489.901 33 204.203.237.144 TCP_MISS/302 165 GET
http://www.cbvcp.com/ - DIRECT/www.cbvcp.com -
908807490.308 298 204.203.237.144 TCP_MISS/200 24884 GET
http://metro.cbvcp.com/cbvcp/ - DIRECT/metro.cbvcp.com text/html
908807491.076 117 204.203.237.144 TCP_MISS/304 119 GET
http://metro.cbvcp.com/cbvcp/graphics/lighoff.gif - DIRECT/metro.cbvcp.com -
908807491.772 51 204.203.237.144 TCP_MISS/304 119 GET
http://metro.cbvcp.com/cbvcp/graphics/newsico.gif - DIRECT/metro.cbvcp.com -
908807492.014 52 204.203.237.144 TCP_MISS/304 119 GET
http://metro.cbvcp.com/cbvcp/graphics/entertainico.gif -
DIRECT/metro.cbvcp.com

Config File:
http_port 8080
visible_hostname cache.3-cities.com
acl QUERY urlpath_regex cgi-bin \? ssi
no_cache deny QUERY
cache_mem 48 MB
cache_mem_low 70
cache_mem_high 85
maximum_object_size 16384 KB
ipcache_size 1024
ipcache_low 90
ipcache_high 95
cache_dir /cache1 3300 16 256
cache_dir /cache2 3300 16 256
cache_access_log /log/access.log
cache_log /log/cache.log
cache_store_log none
cache_swap_log /cache2/swap.log
pid_filename /log/squid.pid
ftp_user Squid@
ftp_list_width 40
dns_children 24
redirect_children 12
positive_dns_ttl 6 hours
connect_timeout 120 seconds
request_timeout 120 seconds
client_lifetime 1 day
announce_period 1 day
httpd_accel_host virtual
httpd_accel_with_proxy on
httpd_accel_uses_host_header on
logfile_rotate 10
append_domain .3-cities.com
forwarded_for off
client_db off
buffered_logs off
icon_directory /usr/local/squid/etc/icons
snmp_port 3401
Received on Mon Oct 19 1998 - 15:49:31 MDT