Vaadin error when using session IPC (JSR-286)

Hello,

I am doing portlet development with liferay 6.1 ga2 and vaadin 6.8.10 for portlet development. I am using IPC extensively. I use both JSR-286 (session IPC) as well as vaadins LiferayIPC.
LiferayIPC is working as expected. However, in the cases where session IPC is used, it is showing a Vaadin error “Communication Problem: Please note any unsaved data” quickly and then firing the event correctly and displaying the proper results issued for IPC.
What confuses me is that I only see this error in firefox and chrome. I cannot produce it in IE7-9. I cannot produce this issue consistently either.
Has anyone had any type of issues like this? I setup IPC closely following http://www.liferay.com/community/wiki/-/wiki/Main/Portlet+to+Portlet+Communication and believe I had it working properly at one point.
One change I made is that now I am passing a larger hashmap (object) over IPC instead of a smaller object used before.
Does anyone have any thoughts on how this could happen?
Is it possible to initializing the same portlet twice and create sync issues?
Any feedback is greatly appreciated and please let me know If you need more information.

Thanks.