Norton 360 v 3.8.0.38 network problem

Running win 7 with Norton 360 v 3.5.2.11 on two networked computers. Both computers were shown in the homegroup and were accessible from either computer. One computer was automatically updated to version 3.8.0.38 and now can no longer access the computer with version 3.5.2.11 nor does it show in the homegroup of that computer.  Any ideas as to why?

Thanks, as it turned out the computer with 3.5 was set to protected.

Running win 7 with Norton 360 v 3.5.2.11 on two networked computers. Both computers were shown in the homegroup and were accessible from either computer. One computer was automatically updated to version 3.8.0.38 and now can no longer access the computer with version 3.5.2.11 nor does it show in the homegroup of that computer.  Any ideas as to why?