On Illustrator for the Mac, I created an file of icons, built from simple stroked vector shapes. I saved it to Dropbox. I opened Illustrator for the iPad, navigated to my Dropbox folder, and opened the file. I saw the warning about how not all features of this (very simple) file were supported by Illustrator for the iPad. I closed the resulting document because I could not work on it.
I later opened the same file on Illustrator for the Mac and those vectors were gone. The only thing left was the proxy low-res images for a reference photo. Luckily I had saved a PDF for my client to preview and I had enabled 'keep editable' in the export options.
My question is, is there a way to prevent AI iPad from writing over files, both 1) at all and 2) especially after giving the user an error warning that the file's features weren't fully supported.