jQuery Form Plugin Error: "Failed to load resource: Frame load interrupted"

jQuery Form Plugin Error: "Failed to load resource: Frame load interrupted"

I'm getting this error when using the jQuery Form Plugin from malsup with a simple form that is uploading a single file and processing it...

Failed to load resource: Frame load interrupted
 
I see this error in webkit... Firebug doesn't seem to provide much help with this one tho Firefox fails too.

Currently processing like this:
1. select the file
2. hit submit (returns false)
3. 'beforeSubmit' runs...
3. it runs, uploads the file, processes the file
4. only when it's at the end of processing it throws above error.
5. 'success' doesn't run due to the error thrown.

Anyone have ideas as to what I'm doing wrong?

Thanks - ignite