Wireshark, F5 plugin and missing Low Details

Hi,

I am playing with Wireshark F5 plugin (great tool!!) and wonder why for some packets F5 Low Detail section is missing. Can't see pattern here.

I used this command to launch Wireshark:

plink.exe -l root -pw pass MGMT ip "tcpdump -w - -s0 -pi 0.0:nnn tcp or udp or icmp" | "c:\Program Files\Wireshark\wireshark.exe" -k -i -

Some packets have all levels, some not. I am using such Wireshark filter to track HTTP session:

(ip.addr eq 10.128.10.2 and ip.addr eq 10.128.10.40 and tcp.port eq 43685 and tcp.port eq 80) or (f5ethtrailer.peeraddr eq 10.128.10.2 and f5ethtrailer.peeraddr eq 10.128.10.40 and f5ethtrailer.peerport eq 43685 and f5ethtrailer.peerport eq 80 and (f5ethtrailer.peeripproto eq 6 or (f5ethtrailer.peeripproto eq 0 and tcp))) - actually it's created by Analyze -> Conversation Filter -> F5 TCP command in Wireshark

Here is capture:

Packet 686 has Low level

but packet 688 not

It happens for other packets but why - any idea?

Piotr