Problem with burning footage onto 3 DVD+RW on the fly by using InCD 4.3.0.5

Dear Sir/Madam,

We are using Nero6 (Version 6.3.1.25) with InCD (Version 4.3.0.5) to burn 3 DVDs (DVD+RW X 4 disks) on the fly.
We are saving to HDD at the same time.

Our computer specification is as follows:

CPU : P4 2.4GHz
RAM : DDR 512Mb
Motherboard : Asus P4P800
HDD : Maxtor 160G IDE
3 DVD Burners - 2 Pioneer DVR-107D and one Sony DW-U18A burner (both supports DVD+RW X4). Sony burner is on the same primary IDE bus with HDD, and both Pioneer burners are on the same secondary IDE bus.

The files we are burning on the fly to 3 DVD are four MPEG4 video footages (each video generates 64KByte/s CONSTANT data rate as the recording goes)
or only ONE MPEG4 video footage (generates 312.5KBytes/s Constant data rate) onto each one of the DVD disks. The symptoms we are having is lost frames or freezing without any regular or logical explanation.
(What i found was burning only ONE MPEG4 video footage onto all 3 DVDs has less chance of losing frames compared to burning four video footages.)

Please help us

Kind regards