DM - iCal sync deletes past entries

I am having a recurring problem with DM and syncing iCal <--> Blackberry calendar (Pearl 8120 && DM 1.0.3 && MacOS 10.6.4)

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I gave up on this after about a month of various problems, after I first got the phone. It was deleting random entries in the calendar, doesn't (still) work with gmail, assorted all my address book entries and telephone numbers, battery life was rubbish, etc.etc. I was at the end of my tether. So I went back to my old N$�!@ which had worked fine but did not sync at all with my mac. I decided to try again with new DM and MacOS versions a couple of weeks ago, reset the phone completely and started from scratch.
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So, syncing works fine (apart from a 'sync error' on syncing Contacts, although this doesn't seem to affect anything).
BUT: It deletes a chunk of history between 3 weeks prior and 2 weeks prior.
I have DM Calendar settings to 21 days prior & 180 days after.
The BB is set to 'keep forever'.
Google Sync *is not* installed.
Facebook *is* installed, but not set to sync to the calendar.
This is frustrating and irritating. Luckily I am paranoid and keep individual iCal and Address Book backups before I sync (and Time Machine), so I can restore when this happens.

If I cannot sort this the BB is going in the bin and I am either getting a paper diary or an iP0$ Touch.

If you have any suggestions, please, please post them here, or email me.

I noticed that my Blackberry erases anything in my calendar that is older than 60 days.

IT SOMETIMES TRIES TO DO THIS EVEN WHEN I HAVE ALREADY TOLD THE BLACKBERRY TO KEEP APPOINTMENTS FOREVER.

IF WHEN TRYING TO SYNC YOU GET: "Sync Alert: Syncing with BlackBerry desktop Manager will change more than 25% of your calendars, events, or to dos on this computer and then it shows you that it is about to delete a large amount of calendar events. STOP. Click on Sync Later.

There are two ways to resolve this issue.

One is to set advanced settings for Calendar in BlackBerry Desktop Manager for Sync Only Future Events. This will allow you to sync everthing in the future and leave the past untouched but any revisions you made to dates in the past since your last sync will not be Synced.

For a total solution you must do two things:

1) Make sure the BlackBerry is set to keep appointments forever
Go to the Calendar in your blackberry and opening it and then hitting the blackberry option key and scrolling down to Options and selecting Options
then select General Options
Then scroll down under Actions and find Keep Appointments and set this to Forever
Then hit the back key (the curved arrow to the right of the track ball) and select save

2) On your Mac:
Quit BlackBerry Desktop Manager and
Navigate to <User>/Library/Application Support/
Delete the BlackBerryDesktop folder.
Empty the Trash Bin.
Restart BlackBerry Desktop Manager.

In BlackBerry Desktop Manager change all your syncing settings for Calendar, Contacts, Notes and Tasks including advanced settings and Sync. It will alert you that this is your first Sync ever. Choose Merge data for each choice when it asks.

NOTE TO BLACKBERRY: The necessity to occasionally throw out the BlackBerryDesktop folder and resync everything to resolve this problem is clearly a bug in BlackBerry Desktop manager that should be fixed.