SOAP access fails requiring a server restart

After successfully running a large number of requests, basic request fails and following warning message appears in the logs. A server restart is required to get SOAP access working again. Similar activity against earlier Confluence versions has never experienced this problem. It is not know after how many requests before begins to fail, but I have had to restart at least twice in the last 2 hours of running various automated test using the Confluence CLI. Primary activity is storing pages.

2013-09-28 11:17:43,527 WARN [http-8122-6] [confluence.rpc.axis.AxisSoapServer] recycleAxisServlet Initialising AXIS SOAP service (loading)
 -- url: /rpc/soap-axis/confluenceservice-v1 | userName: anonymous
2013-09-28 11:17:43,564 WARN [http-8122-6] [confluence.rpc.axis.ConfluenceAxisServerFactory] getServer getServer
 -- url: /rpc/soap-axis/confluenceservice-v1 | userName: anonymous