Ok, so nginx is running, and mono appears to be running as well (the fastCGI module). The virtual website is responding fine and serves static files but I get the standard "Server error" ASP.net 404 page when I try calling an aspx file (hence mono is running and taking requests). Any ideas?

I've modified the nginx.config file accordingly (I hope) and since I do get the 404 page it is probably configured properly so it might be a mono issue.

Thank you in advance.

One thing I've recently discovered is that there's a way to work around Linux's case sensitivity when running Mono. I suspect that this (or a path problem) may be your issue. Add the following to enable case-insensitivity in Mono applications:

export MONO_IOMAP=all

Add that to whatever script you use to start the Mono FastCGI server.