"No free space in circular buffer" error flood on VirtualBox with PCNETIII

VBox v4.0.8.71778
OS type = Other/other, COM1 = debug.log
RAM = 256Mb, VRAM = 32MB, USB, AC'97, HDD = no
LAN = PcNet-FAST III (disconnected)
CD = livecd-52224-dbg.iso or livecd-52231-dbg.iso or livecd-52236-dbg.iso and maybe others..

Steps:
1) run ReactOS and do nothing
2) wait 4-7 minutes
3) operating system collapses messages

(drivers/network/dd/pcnet/pcnet.c:1163) No free space in circular buffer
(drivers/network/ndis/ndis/miniport.c:871)(MiniQueueWorkItem) Requeuing failed packet (ffa300a8).

and in fact ceases to respond to the actions. (code "ffa300a8" always different)