Pastes from Excel using Screen getExternalSelection show black rectangles

Hello.

I've checked through the posts and don't see anything addressing this issue.   I  am using Screen -> getExternalSelection to grab the clipboard content on one system so I can paste into my VW application on another system.  I'm going from Windows -> Linux

This works fine - until the clipboard content reaches a certain size.  If I look at the string returned I see the end portion of the string is all black rectangles.   For the tests I've been doing it's happening at around the 262K element in the string that's returned.  

I've done some tests taking one row of a spreadsheet, pasting, then taking 10 rows, pasting, etc.   At some point as I increase the row size I eventually see the black rectangles.  

Does anyone have any experience with this or alternate methods to take clipboard contents (ByteArray) and paste?

Thanks,
Karyn Hurley
Global Foundries