I vaguely remember that indeed Mint hasn't added LVM support. The only I truly remember is that when I setup Ubuntu 10.04 LTS server edition. This one has LVM setup support right into the installation stage.
So speaking of choice, IMHO it's a bit limited. But since there's a chance you did downgrade (10.10 to 10.04, right?), I suggest to do full data backup and start over from scratch. That way, you could start fresh.