I had the same problem so I modified it to work on nop 2.30 and also added some code to pass the shopping cart items to the sage pay server. I have try it in the test server with a UK visa transaction and it seems to be working.
I'm working on a project that requires SagePay Server integration with v2.3 also. I've tried to download your files from SkyDrive but it looks as though the file/s have gone? Could you help at all?
yes I disable it because is not 100% functional as as for example iframe checkout doesn't work properly nor does one page checkout.
For me is ok as I am not using either of them. I you think this will be good for you then PM me and I'll send you the code and you can use it as your own risk :)