Just wanted to thank
CheronAph for his hint about raising the VBV buffer!

I recently ran into this dredead illegal floating decimal point calculation order problem (yet again!) on some cartoon DVDs I was converting (by the way, I only seem to come across this error while converting fullscreen anime/cartoon sources).
Anyways, I had tried
every single hint listed in the long thread in the TMPG forum about this issue, and nothing worked! (even "fixes" that had previously worked for me). Even a bare avs script with no filters would not work. I finally tried
CheronAph's tip, and it worked! I tried a VBV of 50 and it worked for most of them, but I had to go as high as 70 on a couple as well. It did increase filesize a little bit, but was well worth it since it saved me a big headache...and the resulting files play fine on my dvd player.
So I definetly would recommend trying this VBV buffer fix to anyone experiencing Illegal Floating Decimal Point errors.
-d&c