[14:19:53.80] C:\test>984648-3.pl 500MB.csv junk.txt
1343827530.71078
1343827532.87958
1343827533.36184                          ## Delta here several minutes
1343827536.56099

[14:25:36.61] C:\test>984648-3.pl 500MB.csv junk.txt
1343827536.68696
1343827538.87822
1343827539.3639                           ## delta here a gnat's under 7 seconds!
1343827543.53711

[14:25:43.58] C:\test>