It's getting late here (3:15), so I probably won't get it done tonight. If I do I will send you what I get and post something here saying I sent it to you.
EDIT: if you're still on, check your mail, I don't think there is a problem at all.
The way lz77 compression works is that it finds places where code is repeated and then referrences back to the original string. Because of this, the files can come up smaller or larger depending on whether there is more or less repeated code. In the case of your .bin file it came up smaller because of more repeating segments. However when you recompressed the .pac, your new compressed .bin had less things that were used by the other files in the .pac, so it ended up larger. Brawl has about 400mb of padding. If you insert the new file with WiiScrubber it can insert the larger .pac and it will just overwrite some of the dummy data.
EDIT: if you're still on, check your mail, I don't think there is a problem at all.
The way lz77 compression works is that it finds places where code is repeated and then referrences back to the original string. Because of this, the files can come up smaller or larger depending on whether there is more or less repeated code. In the case of your .bin file it came up smaller because of more repeating segments. However when you recompressed the .pac, your new compressed .bin had less things that were used by the other files in the .pac, so it ended up larger. Brawl has about 400mb of padding. If you insert the new file with WiiScrubber it can insert the larger .pac and it will just overwrite some of the dummy data.