Intermittent problem of CRX repository bundle not starting after installing auth login module bundle in publisher instance

Bundle "Day CRX Sling - CRX Embedded Repository (com.day.crx.sling.server)" does not come up after installing few project specific bundles, especially bundle containing custom auth login module. 

This is intermittent problem and it starts working fine once I restart CQ instance. Is it some classloader issue? 

Screenshot of system console which shows bundle in STOPPING status.

[img]error.png[/img]

I see following exceptions in logs

19.12.2014 03:54:37.999 *WARN* [FelixFrameworkWiring] com.adobe.granite.crx-explorer [com.day.crx.explorer.impl.compat.BackupServlet] Could not get service from ref [com.day.crx.sling.server.jmx.ManagedRepositoryMBean]
19.12.2014 03:54:37.999 *ERROR* [FelixDispatchQueue] com.day.crx.sling.server FrameworkEvent ERROR (org.osgi.framework.ServiceException: ServiceFactory.getService() resulted in a cycle.) org.osgi.framework.ServiceException: ServiceFactory.getService() resulted in a cycle.
    at org.apache.felix.framework.ServiceRegistry.getService(ServiceRegistry.java:272)
    at org.apache.felix.framework.Felix.getService(Felix.java:3556)
    at org.apache.felix.framework.BundleContextImpl.getService(BundleContextImpl.java:468)

    -  - - - - - 
    - - - - - - -
19.12.2014 03:54:38.001 *ERROR* [FelixDispatchQueue] com.adobe.granite.crx-explorer FrameworkEvent ERROR (org.osgi.framework.ServiceException: Service factory returned null.) org.osgi.framework.ServiceException: Service factory returned null.
    at org.apache.felix.framework.ServiceRegistrationImpl.getFactoryUnchecked(ServiceRegistrationImpl.java:341)
    at org.apache.felix.framework.ServiceRegistrationImpl.getService(ServiceRegistrationImpl.java:219)
    at org.apache.felix.framework.ServiceRegistry.getService(ServiceRegistry.java:320)