Two executions of the tomcat7 plugin in the same build makes the JNDI context of the second execution fail

When starting only one instance of a tomcat7 server with the run-war-only mojo, it works.
If I start more than one server (necessary in our project as our integration tests include interaction between several deployments of the app with various configurations), all servers after the first one fail to deploy with a jndi lookup error:

javax.naming.NameNotFoundException: Name [comp/env/jms/ConnectionFactory] is not bound in this Context. Unable to find [comp].
org.apache.naming.NamingContext.lookup(NamingContext.java:820)
org.apache.naming.NamingContext.lookup(NamingContext.java:168)
org.apache.naming.SelectorContext.lookup(SelectorContext.java:158)
javax.naming.InitialContext.lookup(InitialContext.java:392)
org.springframework.jndi.JndiTemplate$1.doInContext(JndiTemplate.java:154)
org.springframework.jndi.JndiTemplate.execute(JndiTemplate.java:87)
org.springframework.jndi.JndiTemplate.lookup(JndiTemplate.java:152)
org.springframework.jndi.JndiTemplate.lookup(JndiTemplate.java:178)
org.springframework.jndi.JndiLocatorSupport.lookup(JndiLocatorSupport.java:95)
org.springframework.jndi.JndiObjectLocator.lookup(JndiObjectLocator.java:105)
org.springframework.jndi.JndiObjectTargetSource.afterPropertiesSet(JndiObjectTargetSource.java:97)
org.springframework.jndi.JndiObjectFactoryBean$JndiObjectProxyFactory.createJndiObjectProxy(JndiObjectFactoryBean.java:285)
org.springframework.jndi.JndiObjectFactoryBean$JndiObjectProxyFactory.access$0(JndiObjectFactoryBean.java:276)
org.springframework.jndi.JndiObjectFactoryBean.afterPropertiesSet(JndiObjectFactoryBean.java:177)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1479)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1419)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:518)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:455)
org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:293)
org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:290)
org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:192)
org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:567)
org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:895)
org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:425)
org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:467)
org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:483)
org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:358)
org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:325)
org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:127)
javax.servlet.GenericServlet.init(GenericServlet.java:160)
org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:99)
org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:929)
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1002)
org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:585)
org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:310)
java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
java.lang.Thread.run(Thread.java:662)