Trouble backing up KOTORII (SecuROM 5)

I’m trying to make an emulation-free copy of Knights of the Old Republic II, which A-Ray has informed me has SecuROM 5 protection. I haven’t been able to find much about SecuROM 5 on the net. The only guide that appears to be legitimate is philamber’s guide here which is about two years old, but so is the game I’m trying to copy.

Anyway, using that guide, I read the KOTORII disk to an image with Alcohol, patched the new image with TwinCreator, and then I tried to burn, using Alcohol, the mds patched with TwinCreator. Alcohol tells me this:

Not enough space for writing process (CD)
So, out of curiosity, I went back to TwinCreator and patched the original mds with a max image size of only 600MB, which output a patched.mdf of size 772.47 MB, while the 710 max output 787.28 MB.

Now, Alcohol burns my unpatched original mds back to a CD without a problem; this unpatched mds is 772.38 MB. So, obviously, it’s not the actual size of the image that’s causing Alcohol this trouble. My question is what IS causing Alcohol this trouble?

Thanks.