To those of you that have the Quartz add on, you know that it shows you how much lag is being experienced by the current spell cast and is not affected by the "normal" latency meter. I'm just wondering if this is normal for most of you:

Traceroute to the edge of the WoW servers, for me, is usually 200-240ms (quite consistent).
In-game latency meter varies from 300-500ms depending on time of day, server load etc.

Quartz spell cast however, usually records lag from 350 all the way up to 800+. I'm just curious why a traceroute gives a latency of 220ms while casting can lag up to 800ms. It just seems a bit weird to me. Anyone have any ideas why this occurs?