Please supply you AOLserver version. Anyway mine works here is my nslog section of the .tcl file:
ns_section "ns/server/deepsky/module/nslog"
ns_param EnableHostnameLookup "Off"
ns_param File "/home/aol30/log/deepsky.log"
ns_param LogCombined "On"
ns_param LogRefer "Off"
ns_param LogUserAgent "Off"
ns_param MaxBackup "5"
ns_param RollDay "*"
ns_param RollFmt "%Y-%m-%d-%H:%M"
ns_param RollHour "0"
ns_param RollOnSignal "On"
ns_param RollLog "On"
My version has different parameters. I am not sure where I got it from at this point, but I use the same format for several servers.
PS. Please put tags around code samples, otherwise they get bunched up. (and specify HTML when you submit the item)