PIVision: White colour on symbols when using Fill Mode? (Imported Processbook Pictures on PIVision)

Hi.

I've encountered a weird problem the last few days which I hope someone could help me sort out.

In our production we have a few hundred processbook images that are published on PiVision for everybody to view. On Processbook the files (PDIs) look great, but in the last few days I and a few others have noticed that some symbols (not all!) show a white colour on PIVision.

It seems like this only occur on the symbols that uses fill colour.

Example: we use a PIPE Symbol and use a fill colour to change the colour of the pipe). Mostly it shows up fine, but on some of our pictures, the pipe changes colour to white. The same issue occurs with Tank Symbols and Valves (except for Valves linked to multistates, they work fine).

Processbook Image:

The same source file, but viewed via PiVision:

Any ideas why this happens?

- Matthew