Irenic, I just finished downloading the stuff. Yet to flash it. I'll update soon. But for you, here is what I suggest.
Apparently, CM has implemented a new way of using Apps2SD and its getting lots of positive reviews. So much that a custom recovery was made for it. Hence, its almost like reorganizing everything in a different way. Hence, its recommended that you start everything once from the ground base. Next time, you will not need it again. Here is what I suggest you to do.
1. Do a Titanium Backup. Seriously, if you have not yet get the donate version, get it ASAP! This is a life savior in many instances. I might have a special deal for you guys on this later. Still in discussion though.
2. Second, do a nandroid backup.
3. Move everything from your SD card to your computer.
4. Clean wipe your SD card. Reformat it, remake the partitions, optimize it for ext4, plan properly how much space you need for your apps. If you have 8GB, keep 1GB. You will not regret. Although 512MB is more than enough, but you don't want to run out of space when you have hundreds of apps in the future

5. Flash the new recovery if you have not done that yet (this does not apply to you irenic)

6. Flash the radio if you have not yet done.
7. Flash the CM rom.
8. Load up the phone, once you are in, move back all the data from the computer to your phone.
9. Install all your apps from the Titanium backup.
10. Go to the market, for ALL the apps that you have, go into them one by one, uninstall it, reinstall it, move to the next one. All your apps will be moved to SD card. Those that you don't uninstall and reinstall, will remain in your phone memory.
Please note, before anyone say anything about this method, bear in mind, this is a method for EVERYONE. A fail-proof method which will definitely work. If you want to avoid ANY problems, just follow these and you will be just fine.
For issue reports, please report to our community forum. You'll get faster responses there.
Great post Shahz. Now if you'd be kind enough to slip in some links to app2sd and the latest recovery image 1.7.
Anyways, I'm holding onto to my CM5.04 till there is a clearer picture on 3g issues in CM5.05