I'm an idiot. I have a new 8310 from AT&T, which came with OS 4.2 and Desktop 4.3.

Here's the story:

1. I tried to upgrade the OS to 4.5, following directions I found on this forum.
2. I didn't follow the directions completely, because I a. didn't delete the vendor.xml file before updating, and b. I didn't use Desktop 4.2.2.
3. OS 4.5 seemed to install correctly, but the Media Manager would not work. So I updated the DM to the newest, 4.6.
4. Now the unit will not sync. It synced correctly with DM 4.3, but not 4.6. It hangs up while syncing the calendar, "Application Terminated Unexpectedly" or something like that.

Can I undo all the upgrades and just put the unit back like it was before? My understanding is that I can't undo the OS upgrade; is that correct?

I just want to be able to sync my address book and calendar and to do list. HELP! Is there any hope for me?

PLStepp

I believe you can't upgrade the OS unless you delete Vendor.xml, unless the vendor that released the OS is the vendor of your phone...so if you didn't delete it and you still upgraded, that's not an issue.

You can do the upgrade w/any version of DM...4.2.2 is not required.

You can uninstall DM 4.6 and download and install DM 4.5...I've seen posts that 4.6 may be problemmatic. I've had no trouble syncing w/DM 4.5.

And you don't have to use Media Manager - you can copy music/files to your SD card directly.

If the OS is running OK on your Curve, no reason to undo that - leave well enough alone.

Stay calm....

I found the same issue with DM 4.6. I'm assuming your not on BES so just uninstall DM and install an older version. Now install the carrier OS (4.2) and when you connect your BB the app loader should show the old OS and erase and downgrade.

When done just resync how you did and resend your service books via BIS website / BES.

I'd still recommend not downgrading the OS unless you have a problem w/your Curve.

I don't believe that DM can or will do any "automatic" OS downgrade of your Curve in any case...downgrading an OS is more involved than that.

Nope - I was wrong, it is that easy. Uninstall the newer OS, make sure the older OS is installed (or reinstall it if you removed it) and connect your BB and open DM and run the app loader...

How do I downgrade the OS on my BlackBerry? - BlackBerryFAQ

Is there a *chance* that a problem with Flash, iTunes, or FireFox is related to this?

I ask because iTunes upgraded a couple of weeks ago, and FireFox has gone nuts ever since. When I get a chance, I need to uninstall and reinstall all three.

Would one of them have an effect on DM?

Doubtful, never heard that DM makes use of flash, nor any connections to Firefox.

So just use Windoze ADD/REMOVE to uninstall, then install a DM other than 4.6?

Any residual files I need to delete? Anything else?

OK I tested this when I got in.

DM 4.6

Removed the 4.5 OS installer so nothing showed under DM / Help / About / Device

Installed current At&t OS (4.2)

Plugged in BB (4.5) and went through application loader

THANK YOU, THANK YOU, THANK YOU.

The Outlook issue turned out to be an old, old entry in the calendar that had a non-standard character. Probably I had copied and pasted something with an em dash or a smart quote or whatever into the title of an event.

Once I deleted it, and about fifty billion other old appointments from the Outlook calendar, everything was fine.

See - calmness is rewarded.

Glad you're up and running again.