jboss7 upgrade + seam + jsf Configuration Failed error on deployment - jsf

Question

I'm currently upgrading my Jboss5 project to Jboss7. As of now, we still have seam2 and jsf 1.2 integrated into the project. Those will eventually be phased out/upgraded, but for now I just need the application to deploy. I've worked through a ton of bugs, but am stuck on this one:
16:53:49,285 ERROR [org.apache.catalina.core.ContainerBase.[jboss.web].
[default-host].[/xxx]] (MSC service thread 1-1) Exception sending
context initialized event to listener instance of class
com.sun.faces.config.ConfigureListener: com.sun.faces.config.ConfigurationException: CONFIGURATION FAILED! org.jboss.seam.jsf.SeamApplicationFactory
at com.sun.faces.config.ConfigManager.initialize(ConfigManager.java:215) [jsf-impl-1.2_15-jbossorg-2.jar:1.2_15.jbossorg-1-20111019-SNAPSHOT]
at com.sun.faces.config.ConfigureListener.contextInitialized(ConfigureListener.java:200) [jsf-impl-1.2_15-jbossorg-2.jar:1.2_15.jbossorg-1-20111019-SNAPSHOT]
at org.apache.catalina.core.StandardContext.contextListenerStart(StandardContext.java:3392) [jbossweb-7.0.13.Final.jar:]
at org.apache.catalina.core.StandardContext.start(StandardContext.java:3850) [jbossweb-7.0.13.Final.jar:]
at org.jboss.as.web.deployment.WebDeploymentService.start(WebDeploymentService.java:90) [jboss-as-web-7.1.1.Final.jar:7.1.1.Final]
at org.jboss.msc.service.ServiceControllerImpl$StartTask.startService(ServiceControllerImpl.java:1811)
at org.jboss.msc.service.ServiceControllerImpl$StartTask.run(ServiceControllerImpl.java:1746)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) [rt.jar:1.7.0_75]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) [rt.jar:1.7.0_75]
at java.lang.Thread.run(Thread.java:745) [rt.jar:1.7.0_75]
Caused by: java.lang.InstantiationException: org.jboss.seam.jsf.SeamApplicationFactory
at java.lang.Class.newInstance(Class.java:364) [rt.jar:1.7.0_75]
at javax.faces.FactoryFinder.getImplGivenPreviousImpl(FactoryFinder.java:537) [jsf-api-1.2_15-jbossorg-2.jar:1.2_15.jbossorg-1-20111019-SNAPSHOT]
at javax.faces.FactoryFinder.getImplementationInstance(FactoryFinder.java:405) [jsf-api-1.2_15-jbossorg-2.jar:1.2_15.jbossorg-1-20111019-SNAPSHOT]
at javax.faces.FactoryFinder.access$400(FactoryFinder.java:135) [jsf-api-1.2_15-jbossorg-2.jar:1.2_15.jbossorg-1-20111019-SNAPSHOT]
at javax.faces.FactoryFinder$FactoryManager.getFactory(FactoryFinder.java:717) [jsf-api-1.2_15-jbossorg-2.jar:1.2_15.jbossorg-1-20111019-SNAPSHOT]
at javax.faces.FactoryFinder.getFactory(FactoryFinder.java:239) [jsf-api-1.2_15-jbossorg-2.jar:1.2_15.jbossorg-1-20111019-SNAPSHOT]
at com.sun.faces.config.processor.FactoryConfigProcessor.verifyFactoriesExist(FactoryConfigProcessor.java:187) [jsf-impl-1.2_15-jbossorg-2.jar:1.2_15.jbossorg-1-20111019-SNAPSHOT]
at com.sun.faces.config.processor.FactoryConfigProcessor.process(FactoryConfigProcessor.java:132) [jsf-impl-1.2_15-jbossorg-2.jar:1.2_15.jbossorg-1-20111019-SNAPSHOT]
at com.sun.faces.config.ConfigManager.initialize(ConfigManager.java:205) [jsf-impl-1.2_15-jbossorg-2.jar:1.2_15.jbossorg-1-20111019-SNAPSHOT]
... 9 more
16:53:49,338 ERROR [org.apache.catalina.core.StandardContext] (MSC service thread 1-1) Error listenerStart
16:53:49,340 ERROR [org.apache.catalina.core.StandardContext] (MSC service thread 1-1) Context [/xxx] startup failed due to previous errors
16:53:49,354 INFO [org.quartz.core.QuartzScheduler] (MSC service thread 1-1) Scheduler xxxScheduler_$_NON_CLUSTERED shutting down.
16:53:49,356 INFO [org.quartz.core.QuartzScheduler] (MSC service thread 1-1) Scheduler xxxScheduler_$_NON_CLUSTERED paused.
16:53:49,361 INFO [org.quartz.core.QuartzScheduler] (MSC service thread 1-1) Scheduler xxxScheduler_$_NON_CLUSTERED shutdown complete.
16:53:49,380 ERROR [org.jboss.msc.service.fail] (MSC service thread 1-1) MSC00001: Failed to start service jboss.web.deployment.default-host./xxx: org.jboss.msc.service.StartException in service jboss.web.deployment.default-host./xxx: JBAS018040: Failed to start context
at org.jboss.as.web.deployment.WebDeploymentService.start(WebDeploymentService.java:95)
at org.jboss.msc.service.ServiceControllerImpl$StartTask.startService(ServiceControllerImpl.java:1811) [jboss-msc-1.0.2.GA.jar:1.0.2.GA]
at org.jboss.msc.service.ServiceControllerImpl$StartTask.run(ServiceControllerImpl.java:1746) [jboss-msc-1.0.2.GA.jar:1.0.2.GA]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) [rt.jar:1.7.0_75]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) [rt.jar:1.7.0_75]
at java.lang.Thread.run(Thread.java:745) [rt.jar:1.7.0_75]
I've read that the cause might be some jar conflicts, but I'm struggling to find out which ones are causing problems. The project was previously running with jsf 2.2 (I believe, definitely something over 2), but I downgraded it to 1.2 for the time being due to a conflict with Seam 2.0.
Any help would be greatly appreciated. Thanks!
Update
I should have been more specific - I am upgrading to JBoss 7.1.1