It might be an Aria issue more than a chipsounds issue, but I'm not 100% sure. I was trying chipsounds 1.501 as a non registered user and I found that the arpeggiator doesn't work with existing Garritan samples on my computer. Is it because the controls used for the arpeggiator interfere with the expression controls of the Garritan instruments? There is a fast workaround for this, by running two instances of chipsounds, the first one sending arpeggiated midi to the second one, but I think that it would be nice seeing it work in the same instance.
My 5 cents on this.
Thanks for creating such a great piece of software.