The W's indicate that a thread is waiting for disk. It implies you either have a remarkably slow disk (like the original Toshibas shipped in 1999) or that the disk is generating a lot of errors. It has very little to do with the amount of memory you have installed, or the amount you are reserving for cache.

If you get audio stutters, the most likely place for this to happen is near the start of a track, within the first 5 seconds of playback. The playback cache spits out what it has cached and is expecting more data from the disk, which it is not getting in time - hence a brief pause. No amount of reserved memory will help in this situation if the data is simply not being delivered on time.

Other, continuous audio stutters occuring rapidly during playback also point to a failing disk or one with high latency.

ksock is a kernel socket operation. The socket error -32 is FFE0, the meaning of which as an Errno in Unix escapes me at the moment.

This implies you have an IP stack fault of some sort. Have you had serious electrical problems on this unit? It may imply subtle electronic damage which may also account for the apparent slowness of the disk, as the ethernet chip and the IDE interface are on the same buffered databus/5V power rail. You may have a damaged bi-directional databus buffer chip which is causing data corruption.