Nosfer@tu: I'd prefer if people got any unreleased code from me personally, mainly because anyone who gets it needs to know that any problems with it need to be reported to me (our Technical Support folks are doing enough good work looking after the QA-approved product, and I don't want them getting calls from customers struggling with experimental code).
Anyway, to answer the original problem with respect to AutoInstall, Vincent (who is actually one of the other developers here at Ghost HQ with me, despite not having the offical tag under his name) is absolutely correct that this is a limitation of the AutoInstall file format (it internally uses 32-bit file locations) rather than a filesystem limitation.
Vincent and I have discussed techniques for resolving this, however neither of us has been given the go-ahead from management to do this work just yet. We've had a couple of requests recently for improvements to AutoInstall and although I can't promise anything I'll pass this up the chain - our management don't have a lot of detailed data about how all the different pieces of GSS are being used to prioritise enhancements, so requests like this are very welcome.