I've moved your question to the Photoshop General forum for better answers.
What's the document name when it's open but not yet saved?
The name of the file is Little Wekiva III. After saving, the name is PT-GuipanoLittle Wekiva III.
Photoshop itself does not do that.
And since the filename contains PT gui pano -- I'm guessing that the PT GUI is somehow involved.
[Deleted - I see that PT GUI is a pano program.]
This is what I thought as well. I asked about it on a PT Gui forum and they said they have no idea and that there is nothing in PT Gui that would cause this to happen.
My workflow involving PT Gui is to open multiple files from LR or PS or PT Gui into PT Gui. Create a pano and save it to PS with layers. Edit the pano in PS and bring it into LR.
My guess is that when I saved a pano in PS, something ocurred to influence PS to insert (PT-GUI pano) into the file name when I save a file in PS.