During last night I have seen two times a problem into the PMS System. I sent an e- mail message to Miles about it and I am trying several command to solve the situation when it will occur.
This night the PMS was unblocked succesfully two times after a series of command. Only a case ?
This is the MAREX-NA ISS Amateur Radio Status with an explanation about the "Message 33 bug".

Claudio IK1SLD
ISS Amateur Radio Status: November 18, 2002

Packet Mail "Message 33 bug"

By Miles Mann WF1F,
MAREX-NA (Manned Amateur Radio Experiment, North American Division)

Packet Mail "Message 33 Bug":

There is a minor yet reoccurring problem with the Amateur Radio Personal
Message System (PMS) on board ISS. Intermittently the PMS will fail to
display the list of messages stored in the memory of the PMS and the PMS
will not save any new messages. The OLD messages have not been lost,
they are still in RAM memory. This problem seems to be happening once
or twice a week. We have been seeing this problem frequently over the
past few months. The problem is called the "Message 33 bug" and it seems
to clear up bye its self. The longest we have seen this bug on
consecutive orbits is 8 hours, however, most times it clears up within a
few minutes.
When the problem does clear, all of the old mail still appears to be
saved in memory with out any lose of old mail.
All new mail received while in the Message 33 Bug mode is lost.
If you attempt to send a packet message into the PMS, while it is stuck
in the "Message 33 Bug" mode, your new message will NOT be saved.
Here is what seems to be happening.
You log in, not knowing the PMS is stuck in Msg 33 mode, and then you
send a message to the ISS PMS.
The TNC will respond and tell you the message has been saved
"Message saved as Msg # 1926"
Then if you try to do a listing (L or M) you will not see the message
number which was saved. Several stations in a row will all get the same
exact number "Message saved as Msg # 1926".

How to tell if the TNC is in Message 33 bug mode:
We do not want to use up too much bandwidth, by having everyone using
the LIST command before sending a packet mail message. That would be
just too wasteful. Instead, I will suggest that you use the M (read
Mine) command. After you have successfully uploaded a NEW message into
the PMS and closed the NEW message with the /EX command. Then use the M
command to list all of the message TO/FROM your call sign. The M
command will only list message with you call sign in the To or From
fields. The M command will save time and if your new message number is
listed, then your message has been SAVED.

Help list definition:
M(ine) M [CR] lists the 10 latest messages to/from your callsign.

Example
CMD(B/H/J/K/KM/L/M/R/S/SB/SP/ST/SR/V/?)> M
Msg # Stat Date Time To From @ BBS Subject
1743 P 02/09/01 00:18 RS0ISS WF1F FREQUENCIES
1741 P 02/09/01 00:04 WF1F RS0ISS HELLO

Here is what the Message 33 Bug looks like:
When the normal List command is issued, the TNC will display only 1
message, and that message will always have the number 33. If you know
the TNC is having this problem, then please do not try to upload any new
mail. Just log off and try again on a different day.

Msg # Stat Date Time To From @ BBS Subject
33 P 30/20/79 61:4D 7, 200 m99i> m99MR í9?>@í9>>

15368 Bytes free

Only message number 33 was listed. This message appears to be an old
corrupted messages. You should also note, that over 70% of the memory
has been used up. The Date is also the 30th month of the year 1979.

What Causes the Message 33 Bug:
We do not know for sure. There are a few theories which are being
looked into.
Here are some suggests that may help reduce the frequency of the
problem.
1. Do not log into the unused keyboard port. The RS0ISS port is not
used. Just use the Mail box call sign RS0ISS-1 port.
2. Always end your email messages with the /EX command. Never use the
Control-Z command.

Old mail manually cleared:
Last week I noticed the 64k mail box on ISS was getting full. Since we
have been seeing the Message 33 bug frequently, I informed commander
Valery Korzun of the problems and asked him to clear out some of the old
junk mail.

Memory November 10, 2002 = 29737 Bytes free

On November 18, the mail box had been cleared of all except 11 new
messages and the free memory had increased

60990 Bytes free
Next message Number 601
Mailbox selected: 0

If you are not sure of the correct procedures for using the ISS PMS,
please review the information on the MAREX web page. The information
has been posted in three languages.

http://www.marex-na.org/fileshtml/unprotopage.html

www.marex-na.org

Copyright 2002 Miles Mann, All Rights Reserved. This document may be
freely
distributed via the following means - Email (including listservers),
Usenet,
and World-Wide-Web. It may not be reproduced for profit including, but
not
limited to, CD ROMs, books, and/or other commercial outlets without
prior
written consent from the author.

Until we meet again

DOSVIDANIYA Miles WF1F