Packing/Injecting .rez files

I am just trying to edit sounds in SA, and I finally got into the rez files using the gvi.dat/temporary folder method. I have edited the files that I need to, but now I am having trouble repacking the rez file.

rezinject says that there is an error with the rez file, so I cannot reinject it as is. Is there a way to simply create a rez file from the folders/files that I currently have?

Thanks!