Problem Opening Pages In New Tab With RunLocally=true

I am running Firefox Portable with RunLocally=true because I have Firefox Portable set up on a file server, and multiple people will be accessing it from different workstations. I have it set to true to it will copy it locally to their workstation so changes will not be made to Firefox Portable on the file server.

I am having a problem opening links in new tab from a new process. I have -new-tab set on the AdditionalParmaters line to open new links in a new tab.

Here are the steps I am doing to try and get this to work.

1. Run firefoxportable.exe http://www.yahoo.com
2. Run firefoxportable.exe http://www.google.com

I get an error message saying another instance is already running. The link to Google will not open in a new tab in the existing window.

If I turn RunLocally off and set it to false, this works. Google will successfully open in a new tab in the existing window.

Is there a way to get this to work with RunLocally turned on?

Thanks for your help,
Chris