Reader Chris Watkins, like some other people, has a couple of bones to pick with Pages. He writes:
I downloaded the new version of Pages and I discovered that when I opened an old Pages document and made a change, I could no longer open it with the old version, which I find more capable. Also, I can't seem to send these file through Gmail. Can you offer any help?
Some. As has been widely reported, today's Pages differs from the Pages of old in significant ways--most troubling to many people is that features found in the previous version are missing in this year's Pages (the other iWork applications have received the same criticism). And, as you've discovered, when you open an old Pages file in the new version and make even a single change to the document, the file format likewise changes and you can't open that document in Pages '09. What to do?
First, if you don't want your old documents changed, select one that hasn't yet been touched by the new Pages, press Command-I to bring up the Info window, and in the Open With area select your old version of Pages. Then click the Change All button below. This ensures that when you double-click on a Pages file, it will open in Pages '09. Note: This will cause any documents created with the new version to try to open in the old Pages. And when that happens you'll see an error message, indicating that "The required index.xml file is missing" and the file won't open.
So, are files that you've already opened and changed in the new Pages lost forever to Pages '09? Not entirely. Within Pages 5 (the new version) you can choose File > Export > Pages '09. (Keynote and Numbers have similar options for exporting their files to the old iWork '09 versions.) These exported files will open in the old version. However, if you've lost content in the transition from the old file format to the new one, this won't restore it. Pages 5, for better or worse, has done its work. But at least the files open again in the version of Pages you may prefer.
As for your Gmail issue, you're not alone. Gmail identifies these files as executables and, for security reasons, will not send or receive them (yes, even when they're compressed in a .zip archive). So, even if you're using an iCloud account to send such files, if the person you're sending the message to has a Gmail account (as many individuals and companies do), no joy for you or your message.
Although the executive teams at Apple and Google may not regularly meet for skittles and beer, I have to think that somewhere in Cupertino there's a red phone that connects directly to Google HQ. If that phone hasn't yet been put into service to deal with this issue I expect it soon will be.
Until this is ironed out you'll have to send your file in a form that isn't blocked. Again, turn to the Export command and you'll find that in addition to the iWork '09 format it can be saved in the PDF, Word, ePub, and plain text formats. Attach a file in one of these formats and the mail will go through. Or, if you absolutely have to share files in the new Pages format, use a file sharing service such as Dropbox as an intermediary.