I googled "from storage engine", found the list of MySQL error codes (this one must have been 1030, by the way), and did a little more googling to find error codes MySQL passes along about operating system errors:
http://rackerhacker.com/2007/08/09/mysql-error-codes/This says that error 28 from storage engine means -- no space left on the device.
This seems surprising, since line 256 of PortalAdminArticles.php (SimplePortal 2.3.3) is simply querying the database. On the other hand, The SMF error message describing the problem got written to the error log -- which DOES require storage on the database.
Do you get this error EVERY time you try to view your articles list?
Something is not right here, and you need to talk to your hosting company some more.
In order to have more to talk to them about, please:
1) Put your forum in maintenance mode
2) Add the following line in Settings.php -- right after the line
########## Database Info ##########$db_show_debug = 1;
3) Go to the list of all articles. Now, when the query causes an error, you should see the query that caused the error.
4) remove the $db_show_debug line from Settings.php
5) Bring the forum out of maintenance mode.
If that doesn't reveal anything new to you, please use the phpmyadmin, or whatever tool your host provides, to get more information about the tables involved in this query.
FROM {db_prefix}sp_articles AS a
LEFT JOIN {db_prefix}sp_categories AS c ON (c.id_category = a.id_category)
LEFT JOIN {db_prefix}messages AS m ON (m.id_msg = a.id_message)
LEFT JOIN {db_prefix}topics AS t ON (t.id_first_msg = a.id_message)
LEFT JOIN {db_prefix}boards AS b ON (b.id_board = m.id_board)
LEFT JOIN {db_prefix}members AS mem ON (mem.id_member = m.id_member)
ORDER BY {raw:sort}
Find out from your host how merely doing this joined query could be causing an "out of space" error.
Is the temporary space full for some reason? *_sp_articles is a pretty small table, so I cannot imagine the space required do to the ORDER BY is going to be very large.
Is something else going on in the database temporary space at the same time?