Aerial in background wont show in pdf (civ3d)

This may be a stupid questions but my aerials would show in the plot preview and the pdfs I made yesterday. This morning my plot preview shows the aerial but the pdf wont. I havent changed any settings since yesterday. What could be wrong?

Thanks for any help.

I use 2008 but I have this problem ALL the time with aerials. I think it's a memory problem because they're so large. You could first try reloading the image, but I usually end up having to change the image density (which decreases quality unfortunately). I've never understood why they will print one day and then not print the next, but it happens almost every time.

Ive been working with these files for a month and now today it feels like not working. Ive tried everything detach, re-attach, frames. Trimming the image. There has to be a setting somewhere.Very Frustrating!!

Well I saved everything as is even though still didnt work. Then I just shutdown the CAD and restarted. It now works.

slntkrr - that was what I was going to suggest. Sometimes the computer itself is the problem and doing a full shutdown is the best thing. My computer runs "fast" in the morning and as the day goes on, by afternoon I notice slowdowns and weird things happening.

To correct that problem, I like to re-start my computer during my lunch-break so that it is "fresh" again for the afternoon.