Factory PMI Tag problem

I have a strange intermitten problem with some of my tags indicating that they are disconnected viewing them on the client. When I check out there status on my Kepserver quick client they show good and also the same good status in Factory SQL. I can get this corrected sometimes by launching the factory PMI designer, which seems also at this same time to be a bit slower than others, in starting up. After I logon to the desighner I go back and the tags are working. This happened today when restarting the server. I was wondering if anyone could point me in a direction to resolve this? I have the latest versions of the software from about four weeks ago, but I have seen this before that also. I think there is some type of problem in the gateway, but I have never seen any problems showing up in the status indicators other than the diagnostics showing me what I already know that tag throughput is null at that time in PMI. The only error showing on my Factory PMI Gateway log is the last entry Message:ERROR(305) No session found. You must re-login, Catagory:org.apache.catalina.core.ContainerBase.[mainEngine].[localhost].[/gateway], Thread:http-8080-processor 18