Hooray! I passed the QoS Paper with 964 recently on first attempt :D Passing this exam would be much easier if you had passed the ONT paper. This is because ONT covers most of the topics in 642-642 quite sufficiently. However topics like LAN QoS, traffic shaping/policing, and QoS best-practices are given more extensive coverage in 642-642.
By the way, I also passed my ONT and ISCW papers on 5-Jul-07 and attained my CCNP certification finally on that day :))
One more paper to attempt soon is 642-691 BGP+MPLS before I get certified as CCIP :- ))
Many thanks to all in the forum!