DVD Shrink Problem

I am trying to burn a movie I downloaded with Tytools to my computer. I created the VOB files using Tytools9r18, and then authored the dvd using DVD Styler. Because the movie will not fit on a DVD I am trying to use DVD Shrink to compress it slightly.
However I get the message "out of memory The parameter is incorrect". This is an immediate response, and no processing was performed. I have 512 MB memory and enough space on my HD.
Anybody tried this before? Any luck?

Assistance would be much appreciated (e.g. if people are using a different process to shrink movies to fit onto a DVD).

Thanks,

Gideon.