MySQL Eorror 2006: Server Has Gone Away

server has gone away on UPDATE

[Alberto]

Problem:
"server has gone away" "error 2006"

Action performed:
UPDATE (emphasis on update: insert succeeds) on a TEXT type field.
data attempted to send: 62,000 chars

Server:
MySQL 5.1.11
Operating Server System:
Win XP
Script Interface:
Php

MySql Variables:
'wait_timeout', '28800'
'max_allowed_packet', '1048576'

I can't detect where the possible issue could be - max_allowed_packet shouldn't have problems with 62,000 chars, and the wait_timeout shouldn't be an issue as well, for the error was launched nearly instantaneously.

Any idea?

thank you very much
Alberto

[physics]

That is strange. Is there a fulltext index on that field?

[Alberto]

Nope, no fulltext index; actually the field is not indexed at all - other fields in that table are of course, but not the one that was undergoing the update.

It is true that, once updating the text field, all the other fields were updated too (an html form passed all the data anyway), but, then, only when the 62,000 chars were updating the text field this error occurred.
I found out that shortening the chars I sent (say to 50,000) the error does not occur, but it is still unknown why it occurred with 62,000 chars or so.

yeah, pretty weird. This is why i am looking for ideas, if any.
Thanks