Weird quit error 2 minutes into encode

[Dunnyman]

Press [q] to stop encoding
*** malloc_zone_malloc[6482]: argument too large: 4227793240its/s
frame= 736 q=0.0 Lsize= 4879kB time=24.5 bitrate=1629.9kbits/s
video:3227kB audio:684kB global headers:0kB muxing overhead 24.786408%
bench: utime=70.900s
Size of Fix: 0x914
now reapplying junk-header ....
Now processing /Volumes/Willow/The.House.Of.Usher.1960.avi.ff.mpg [1/2] ...
now reapplying junk-header ....
Now processing /Volumes/Willow/The.House.Of.Usher.1960.avi.ff.mpg [2/2] ...
-------Done--------
Encoding completed on Mon Mar 28 21:52:41 PST 2005


The bold part is the weird one, what does this error mean, and how can I fix it? I've tried to encode this via the ffmpegx presets (VCD, SVCD & DVD) and the mpegenc presets (VCD, DVD) and it happens on all of them.
Should I try a different encode then try to go back to the DVD spec from there?

[major]

Seems like an error with a specific frame. What is your source file?

[Dunnyman]

It's a standard mpeg4 avi file. I quit ffmpegX, rebooted, and retried it using the mpegenc preset for DVD, and it's working, but it's going horribly slow. At the same time, I started another encode using the ffmpegX preset, the mpegenc is at 190 megs, the ffmpegX is at 1.1 gigs. I've never seen such a difference in speed, they're bothing using the same bitrate, aspect ratio, etc. The source files are only two minutes and 23 seconds apart in time, and both were encoded from the original source using the same settings. Usually the mpegenc is much faster than that, why would it be so slow now? Or has the ffmpegX gone so much farther in terms of it's ability to process?