I have seen posts discussing this before but what is happening to me isn't exactly the same. I have set up pipe networks, the pipes have a new catalogue and a style applied to the part. The pipe network has the correct style and all layers on all views etc are set to the correct layer. I data reference the part into a new drawing, the relevant catalogue is in here so when i reference the pipe I apply the setting and select the correct layers etc. The pipe looks fine, the style has a line and hatch shown in plan, the pipe part is on the correct layer also. The problem comes when i create viewports, I want to show two viewports on one sheet, existing and proposed. When i freeze the pipe layer in one viewport the pipe disappears in that viewport...perfect...however when I make tweaks to my original pipe drawing and then synchronize the reference all of a sudden I can see the pipe hatch, this is only the pipe hatch and not the lines, and this hatch is on the C-STRM-PIPE layer. I am having to change this hatch to the proper layer everytime I save my reference drawing, I cannot for the life of me find the setting that is causing this, has anyone any experience of this?