just to be clear, your situation as I interpret it is:
- You have multiple text frames that are linked.
- The content flows from frame to frame.
- You have a paragraph that is split across two frames and you want to force the entire paragraph to one frame or the other?
If this is the case I can think of two options
(BEWARE reflow during editing):
1. as suggested already: Use a frame break
2. adjust the frame-size so that the paragraph either is contained in one frame or reflows in it's entirety to the next frame
I'm going to make a suggestion to include a "conditional frame break" in a future revision