Congratulations. Glad to your issue is fixed. As far as using Time Machine remotely over the internet - it is not practical to try to do that - all though it is possible. The only way that I know to use Time Machine remotely (and assuming MBL is local and the Mac is remote) is to use a VPN tunnel. You would need a VPN router on the home side - and a VPN client on the Mac side (possibly the built-in Cisco IPSEC VPN client). From the Mac you would establish a VPN tunnel to your home network - basically in this scenario all of your home devices would be visible to the VPN client - but by IP address only. You would need to know the pubic IP address of your router (or it’s dynamic DNS URL - if you have that feature enabled - as well as having the internal IP address of your MBL. On your Mac - you would use the Finder / Go / Connect to Server option and mount the TimeMachine share on the MBL by specifying the MBL’s internal IP address as afp://xxx.xxx.xxx.xxx (example 192.168.1.100). You would connect as either guest or admin.
Then you would open Time Machine preferences and select the drive to backup to as the share you just mounted. Time Machine should then backup to your MBL - as long as the VPN tunnel is up and connected. The negative side to this is that is it extremely slow - practically unbearable. For a regular hourly backup - it may actually backup in a reasonable amount of time - but as soon as it decides that it has to perform a verification - or it determines that there is a lot of new data to back up - then it will take forever. I have actually done this - as I have a router-to-router permanent VPN tunnel between my network and the neighbors - and we were able to use time machine backup across the VPN to my Time Capsule - however - it was pretty unbearable and more of an experiment than anything.
The other big negative to trying to do this is the amount of uploading that occurs to your ISP account (or the remote sites ISP account) - this large volume of data (upstream on the Mac side) will mostly likely exceed some ISP limitation and possibly result in your internet access being suspended.
This might work acceptably if you had that the Comcast super-high-speed internet where you have download speeds of 50 megabits and greater and upload speeds approaching 20 megabits. In low speed (typical) internet connections - Time Machine backup is not feasible.
In Lion - for portable mac’s - Time Machine now detects when you are disconnected from your network backup device - and performs hourly snapshot backups on the portable Mac itself - and reapplies those snapshots to the regular time machine backup image once you are back on your regular network. The interesting thing is this only seems to be supported on a MacBook Pro - and it doesn’t seem to be available on the MacBook Air - at least not on my MacBook Air.
Typically I take the MacBook Air with me when I am out - I don’t typically take the MacBook Pro with me - and therefore I have yet to witness the functioning of this “snapshot” feature.
Please remember to click to the Kudos star at the left side of each post if the information you received on this thread was helpful or actually solved your problem.