Seems that any of the 5.3-based betas have an issue with handling huge
numbers of packets.  BitTorrent is one easy way to replicate the
problem.

With a 4501 and 1.2b7, downloading about 400 KBps and uploading 2-3
KBps on BitTorrent pegs the CPU on m0n0wall at 100%.  With 1.2b3 and
earlier I used BT without any issues.

To replicate, get any BT client and download a torrent like:
http://torrent.freesbie.org/FreeSBIE-1.1-i386.torrent

Azureus seemed to be the worst, pegging it at 100% all the time.  ABC
client kept it around 96-100%, still way higher than it should be for
that amount of traffic.  Was steadily 390-410 KBps down and 2-3 KBps
up on both.

(all throughput numbers in B, bytes)

Can anyone else confirm or deny?  

-Chris