RichTextBox problem

[snProgrammer]

I have two RichTextBoxes in a windows form. The first, rtbSource, is loaded from an rtf file. I want to be able to select text from rtbSource and copy it into rtbDestination with all the formatting intact. I do the following:
rtbDestination.Rtf = rtbSource.SelectedRtf

The problem is that sometimes rtbDestination doesn't display the formatting correctly. I know this is the problem because I saved the selected rtf from rtbSource into a file and it looks correct.

The other thing I have noticed, is that I only get this problem when my selection doesn't include the end of the paragraph.

Any ideas?

Thanks!