Tmpgenc 4.0 Batch encode HELP!



I am using tmpgENC 4.0 express along with avisynth and MKVextractgui to convert 720p MKV files to wmv for my 360. When i try to use the batch encode tool, I can only convert one file before it gives me error: not enough memory. Since i have a quad core CPU, Tmpgenc opens 8 instances of ffdshow video decoder, and 4 instances of haali media splitter. when the first video completes, the first 12 decoders don’t exit, and tmpgenc tries to open 12 more for the next video, and thats when my pc gets mad. Is there a setting i should be finding in haali media and ffdshow, or tmpgenc to close down these codecs after each video, or use the same ones already open? What memory needs increasing to accomodate the extra codecs, the paging file, RAM? I have 12- 2 hour converts to do, and i really need them to just all convert at once. I looked in ffdshow settings; all i could find is a setting for running multiple instances, which i turned on even though it was already doing that. Any help or advice at all would be really sweet!
TmpgENC 4.0 Express v.
Avisynth 2.5
MkvextractGUI v.
K-lite codec pack (newest version)
Intel core2 quad 9550 @2.83 ghz, Evga 780i TRI-SLI 1333 FSB, Geforce 9800gtx, 4GB kingston 800mhz DDR2, Antec truepower trio 650, Sound Blaster Audigy