If you read the Conexant patent, the claim is for pre-caching in memory the beginnings of samples before playback to avoid hard drive seek latency as part of a musical instrument. IANAL (I Am Not A Lawyer), but I do have a music instrument patent to my name. My take on it is that if you have, say, a database and pre-cache the beginnings of the records, you\'re not infringing; if you have multiple video streams and pre-cache the beginnings, you\'re not infringing; If you have a digital audio recorder and pre-cache the beginnings of the tracks, you\'re not infringing (although I wouldn\'t want to defend against that one in court); if you have a sampler that reads samples directly from the hard drive without any program specific caching of the beginnings of the samples (as opposed to the OS doing it), you\'re not infringing. Halion does pre-cache the samples according to their info, so I assume they\'ve worked out a license agreement with Conexant.
Of course, none of the above is legal advice, just my personal opinion. If you want legal advice, get a lawyer.