I can see that if your percussion is in the same layer as your notes.

Try importing your percussion into a separate layer. This way, you can drag only the notes into TAB.

Try using the Edit Frame on the TAB staff to turn the x-notes into invisible rests. (I assume you want to keep the regular noteheads visible.)

To access the Edit Frame:

1. Make sure you are in Layer 2.
2. Choose the Speedy Entry Tool
3. Click on a blank part of the page so that no measure is highlighted with the Speedy selection box.
4. The CTRL-Click (I imagine that is CMD-Click on a Mac) on the TAB measure you want to edit.
5. Use the NEXT button in the Edit Frame to find the appropriate Layer-2 entry and deselect the Playback and Note/Rest boxes.
6. Click NEXT enough times to find the next x-note. (I keep an eye on the Duration box to compare the lengths of the notes to confirm I am on the right entry.)
7. Click OK and move on to the next measure affected.

https://usermanuals.finalemusic.com/FinaleWin/Content/Finale/SPFRMDLG.htm?Highlight=%22Edit%20Frame%22 

Thank you for your comments, but sorry to say that there must be a better way. Here I attach the same notation done by Finale 2010 (OS X 10.6.8 Snow Leopard).

The hightlighted area does not have the "White Area" which will cover up the fret number. I am doing the notation for guitar arrangement, which may have a lot of percussion sounds along the way with the normal sounding notes. Which means it will not be practical to put the "X"-notehead (percussion) to another layer, nor make it invisible, because we want to hear that hitting sound. 

I have a high expectation for this new version of Finale, hope there is a better solution for this. I really do not wish to switch to another notation software because of this problem. Please advise. Thanks.    

Chiang Ken Phang,

It looks like you have found a bug.

I suggest that you open a ticket with the folks in MakeMusic’s Tech Support.

In your support ticket you can attach both the Finale 2010 document and the Finale v25 document.