Yeah, provide some details.
Version 5.0 or 5.2RC?
Watermark Editor Created? Text-based? Graphic-Based
Is the catalog upgraded from version 4?
Version 5, PC ... watermark created within LR5. Texted base. Jpg format export. After import nothing appears.
You might try several different fonts in your Watermark. Some fonts don't work well in the WME