new interface/front-end for audiophile system


hi, for 6 years now i have been happily running this system for my music:

music storage: lacie hard disk containing my cd's downloaded using apple lossless
interface: dedicated 2nd hand ibook running itunes
primare pre-amp connected to ibook via a hag usb (thanks jim hag), from usb socket to preamp digital in
genelec active monitors
rel active subwoofer

the music has recently developed intermittent 1 second pauses averaging every minute or so, so something is wrong. it seems ok using my macbook pro as interface, so perhaps the ibook is the problem. maybe it's just a loose usb socket? might a usb hub using the other socket solve the problem?
this might be an opportunity to upgrade the system and perhaps replace the ibook with something better. can anyone suggest something that would leave the majority of my system as it is? thanks
garbo
The reason I asked what type of music you listen to is for tagging. Classical music can be challenging to tag. You may want to experiment with some different music player/management software to see what works best for you.
Metadatics has been useful to me for taggings. Others out there too. Have to say FLAC is best for tags versus WAV and AIFF. Prefer to use AIFF though so I use Metadatics to fix or customize my tags for use with Minimserver. If you are using iTunes use AIFF if possible unless you want to save some space.
thanks. tagging is not an issue for me. i'm using itunes and apple lossless; thought that was equivalent to aiff, just more space-efficient?