Loading all thumbnails takes a long time

[jbick]

supersized waits for all thumbnails to load before it starts a slideshow. This takes a long time for large slideshows (>100 pictures).
It might be related to a server misconfiguration (e.g. worst keep-alive handling in town). However, in my environment we are only allowed to upload static files and we can't change the server configuration.
Is there any way to wait only for the first x thumbnails to load? I thought about using a smaller array in slides and populating it later but the api does not seem to be flexible enough for this.
Any ideas for a fix?