Hi Andrew,
this error means that somewhere cursors aren't being closed when opened. They will stay open until the database user is disconnected, which is probably why you're being forced to close AOLserver.
The following bits of SQL should help you track down which cursors are causing the problem:
select user_name, status, osuser, machine, a.sql_text
from v$session b,
v$open_cursor a
where a.sid = b.sid
/
and
select a.value, b.name
from v$mystat a, v$statname b
where a.statistic# = b.statistic#
and a.statistic#= 3
/
I found these at
http://www.orafaq.com/error/ora-01000.htm.
Hope this helps