In the report view (Window > Report) you can see all the issues that will occur when you select a different version of reader, for example locking fields after signing (something we want to use) will work with version 8 of reader, but not 7.0.5.
We're in a similar position, only options available are to remove the functionality or upgrade the version of reader, but the report will help you identify any issues that you would have.
Now I have a question for you, how do you get the regions to hide/show? I've been trying to find out how to do this for a while now.