Avi to dvd - trouble with output size and bitrate

hello i’ve been using chickenman’s divx/xvid to dvdr guide and it’s been working fine. recently formatted and now im having problems. im putting tv episodes onto dvdr so i set the output size on d2sroba to be 1100. before i was able to fit about 4 episodes per disc and get a bitrate of 9000 with the file size being very close to the 1100 i set. now when i do batch encodes i get output sizes that range from 700-800 something and varying bitrates around 3000-4000. no where near the 9000 i got before. i just did 1 episode without the batch encode and the output came out fine with the correct bitrate. the problem only occurs when i do batch encodes. please let me know what can be done to correct this. thanks in advance.