When i tried to teleport from the Red Dragon Club to the OSG7B regions last night, i received this message : "Destination is a variable-sized region, and source is an old simulator. Consider upgrading.". So i immediately shutdown all regions, and upgraded all servers to the latest build. Not that the regions weren't doing fine, but our visitors should be free to leave to whatever place they like, also if that region is a VAR.
OSGrid only made mention of this fix / change on it's G+ page, so you might have missed it, but the message is pretty self explanatory. If you want to be able to teleport in and out of VAR regions, you have to be on a region running their latest build. Alternatively you can make a hop in-between on either one of the plaza's or another normal size region running the latest build (software version). This is probably to prevent you from running into other problems due to code changes between the builds.
If you just joined OSgrid in the last few weeks, and just have your first build on your regions, now is an excellent time to create a backup OAR (it's a full export of your region / terrain / objects / settings), and upgrade to the latest build. It's not a requirement, but does prevent you and your visitors to "failing" teleports, as you can assume much more people will run VAR regions in the near future.