I think i may have identified a defect on the enabling of the buttons on the ajax carousel.

The updateNextButton works much better when using the following logic:

updateNextButton: function($super) {
    var lastPosition = this.currentLastPosition();
    var size = this.currentSize();
    var nextClassName = "next_button" + this.options.disabledButtonSuffix;
}

if (this.nextButton.hasClassName(nextClassName) && lastPosition == size) {
    this.nextButton.removeClassName(nextClassName);
    this.fire('nextButton:enabled');
}
if (!this.nextButton.hasClassName(nextClassName) && lastPosition <= size && !this.hasMore) {
    this.nextButton.addClassName(nextClassName);
    this.fire('nextButton:disabled');
}