I've been using mapserver + tilecache for quite some time to generate map tiles. recently i am trying to generate tiles on bigger country (i.e. Australia), and it took ages for tilecache to generate all the necessary tiles for the whole 20 zoom levels. i've been stuck on level 15 for weeks. also, I can see that the server memory keep increasing when i run the tilecache for quite some time. it can go up to 8gb++, is there any memory leak or something? it seems that the memory is sort of lost in space and not released. Any idea on this?