WordPress Multisite Problems

We’re currently working on a Multisite WordPress Installation for an educational establishment. The problem is that the server is accessed via a proxy on their main domain.
Their technical people advised us to set up the wp install using the server name. We’ll call it “Gomez”. Gomez isn’t accessible from the internet, so it’s accessed via www.domain.ac.uk/proxyname. That’s fine, except that it only works internally. 🙁
Also, it switches all the URLs back to Gomez once you are through the proxy. 🙁
Using a “requestheader host” statement in the htaccess file throws a WP error – it thinks there’s a port number in the URL!
You wouldn’t believe how difficult it is to change the URLs within a WP Multisite install!
We have to use sql queries to replace all occurrences of the original URL with the new one, for ALL the sub blogs as well as the master one. After editing the wp-config file.
It looks like WP multisite has some way to go before maturity..