Season's greeting all

We run iPrint clustered on Netware 6.5SP8. I've done everything to get Win7 up and running and so far so good. I've installed v5.30 of the iPrint client and can upload drivers and install printers from the list (print.xavier.prv/ipp).

But when I try installing printers via the maps we have setup on our internal intranet, I get "The iPrint client is not installed. Do you want to install it now?" , if I say YES, I get "Unsupported client type".

I've made sure all the cluster nodes and the website have the same client version. Where else should I look to fix this up.