John: Thank you, this is exactly what I wanted. I was indeed inspecting the plist with bbedit, but what I did not realize is that the file has some parts which are binary, so I could not see the PersistentMenu-lastUsedAlarms part by using a text editor. I opened it with Xcode and I did find what you were saying, and erased all the junk that was in there. In fact, the issue I had was also described here:
http://newsgroups.derkeiler.com/Archive/Uk/uk.comp.sys.mac/2010-06/msg02349.html
For some reason, it looks like after some upgrade the program adds were some positive values in the plist and I was stuck with default alarms that were set *after* the events I wanted to set an alarm for.
I did what you suggested, then added by hand new values to the PersistentMenu part of the plist, and I am now happy.
For everybody's information, to know what I did, it is enough to know to add Dictionary items to the PersistentMenu-lastUsedAlarms, with 3 fields:
-- AlarmTypeKey (this determines if you want a sound, or else an email, or else the other default alarm type keys. For example, sending an email is a Number, value 4; having a message with sound is a Number, value 3)
-- AlarmDurationKey: This is a Number, in seconds, that determines when you want your alarm to trigger. E.g: -172800 will be two days before. Must be negative for "before", of course)
-- AlarmParameterKey: This is a String, where you store the value that you want the alarm to have. For example, if you want an email to be sent, the AlarmTypeKey will be 4, as explained above, and this field will contain your email address. Instead, if you want the alarm to be a sound, the AlarmTypeKey will be 3 and this field will have the name of the sound you want (e.g., Basso).
That's it. Thanks a lot for the solution!
l.