NetBeans IDE Dev (Build 20080314171418)
Java: 1.6.0_04; Java HotSpot(TM) Client VM 10.0-b19
System: Windows XP version 5.1

1. Create a VW project and drop 3 buttons and one pagefragment component. 
2. Open the pagefragment component and add one hyperlink.
3. Create a second page and add only that same pagefragment.
4. Bring up page flow editor and draw links from each of page1 buttons to page2
   so that the case 1 thru 3 represents the buttons and hyperlink becomes "case4" to page2
5. Link page2 hyperlink back to page1 as "case1"
6. Deploy and test: all the links work back and forth. OK.
7. Rename the page2 hyperlink's link to page1 as "case9" in the pagefloweditor
8. Deploy and test
>hyperlink from the pagefragment on Page1 is broken

At this point, the workaround is to have all pagefragment links the same name.
So, renaming both links from each page fragment to "case9" (or any other string) 
will restore navigation. I think this workaround needs to be release noted
if this can't be fixed. 

Somehow it works initially when the link names are different.

This bug was also in 6.0 but not in 5.5.1