I'm running 64bit Sonar X3e and a friend is running 32bit Sonar X3e. I want to copy my project folder onto his pc so I can record some tracks at his house. Other than plug-in's will this be an issue? I'm going to remove the 64bit plug-in's from the project. He's running the same sample and bit rate as I am.

32bit and 64bit versions of the same release of SONAR use the same project file format. Should be OK if the 32bit machine has the resources to run the projects.

Steve, I have a dumb question that could only come from somebody still living in a 32-bit world: if you open a 32-bit project in 64-bit SONAR and re-save it, is the newly-saved project file identical to the original?

Yup - just might need to swap out some plugins if they don't have 32-bit versions available.
 
If there ARE some plugins that can't be swapped out, then perhaps he could create a version of the project that has tracks with those plugins bounced, so that you are then dealing with 32-bit audio.
 
Bob Bone
 

The project file format does not change between 32bit and 64bit platforms. The project file format only changes between releases of SONAR.

scook
32bit and 64bit versions of the same release of SONAR use the same project file format. Should be OK if the 32bit machine has the resources to run the projects.

In a sense there is no such thing as a 64 bit Sonar project. Even if you use 64 bit plugins its just a pointer to the plugin not the plugin itself. The audio is stored in its own folder. Therefore, saying its a 64 bit project is a misnomer. Yet we know that 64 bit Sonar and 32 bit Sonar both create projects. The difference is only with what plugins may have been used. 

Perfect! Thanks everyone.