Hmmm...

Using Firefox on a 32 bit Windows box, both PDFs display just fine.

I used to have this problem when moving between Word / Office versions and creating the PDF by printing to the Adobe converter. Since I've been using OO (for about 4 years now and hundreds of documents with embedded pictures viewed by lots of people) I've never had a problem.

Open Office seems to be better at opening Word documents created in different versions than MS Office itself is, especially if Draw objects are involved. Because I am creating manuals, I often use WMFs generated from AutoCad DWGs that are exported from Altium Designer. MS support for WMFs (Windows Meta File) has degraded with later versions - this really shouldn't happen, it is a MS format after all. No such problems with OO.

When I've submitted schematics as PDFs to this forum they were generated by Altium Designer or DXP using CutePDF.

Thanks Brad, that clarifys thing a bit more with that comparison work,
I was pretty computer literate up to XP and IE6 and Mozilla but after that my brain froze up.

I still like XP Pro as an operating system with an obvious file structure and did a bit of gamer writing around 2000 involving Grand Prix Legends with mip files and stuff. Actually I made a full size Lotus simulator with pitch, roll and yaw to the drivers seat driven by electric motors and solenoids and vibrators supplying the noise and track motion. I should do an article on that for 'special projects'. Not quite vintage radio but almost vintage computer now!

Once Win 7/8/9/10 appeared I lost interest in understanding how their minds worked or else I got too old to care.
I guess the systems being used are just too many in number so the best option is to use what works and avoid the others.

The main reason for packaging my sends in PDF was to limit the size, some of my car/coin/radio articles are 100's MB in size, ok when I worked in a big building surrounded by hardware but now being retired and surrounded by a little network its different. I keep my costs down ( being a starving pensioner and worse off since harbourside mansions cut my part pension, i'll have to sell one of my investment properties!) by having a limited file size and leg chained by slooooow up down speeds.

I'll send in native .doc form if its small but will go back to pdf in nuance (which I use for editing PDF's) if its a biggy.
Now that I know that an alt browser like chrome works fine ( stupid me for not trying that sooner) and 99% of readers don't have a problem that should be the end of it.
Cheers, Fred.