Pretty sure this is not a problem with the KML as such. Rather a limitation of Google Maps. It will only show a certain amount of 'styled' content. Then it defaults back and uses unstyled icons etc.
Google havent been forthcoming on what the limits are, and how they enforced (per tile, per kml etc) If want full control, best to use a third party KML parser (not sure if any have inbuilt KMZ support) -- You received this message because you are subscribed to the Google Groups "Google Maps JavaScript API v3" group. To post to this group, send email to google-maps-js-api-v3@googlegroups.com. To unsubscribe from this group, send email to google-maps-js-api-v3+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-maps-js-api-v3?hl=en.