Word 2010 randomly deleting spaces between words

Continuing discussion from this thread. Original problem is quoted below:

I have no printers of any type installed on my system (and haven't had in the past on this install of Windows 7 64-bit, so there's nothing to clean out). My system is thoroughly maintained (I run a site called TweakGuides.com - I know how to keep a Windows system in tip-top condition).

I've also disabled a range of options in Word to ensure that basic documents remain as basic documents, free of smart tags and other unnecessary embedded data. I even disable all autocorrect functions as a matter of course.

I still find that any document I create in Word 2010 will display randomly missing spaces when viewed in Word 2007. It makes no difference if I save the document with compatibility mode on or off, the spaces will repeatedly disappear. If I view the document using Windows Wordpad, I can see that the spaces haven't actually been deleted, so it seems to be a Word 2007-specific issue.

As such, I'm convinced it's a compatibility bug, as within Word 2010 itself these space deletions never appear, only when viewed or edited in Word 2007. This is fairly serious as you can imagine, because it means documents I send to people using Office 2007 (a large proportion of Word users) look sloppy as a result. Editing them is also pointless because as soon as they're saved in Word 2010 and sent back, a similar number of random spaces are deleted.

Now continuing with reply to the suggested answers from the previous thread:

@TerFar - I understand what you're saying, however obviously Word does not need a specific printer driver, or comes with a generic one built-in, or uses a Windows-based generic driver, because I don't have a printer and have never attached one to my system(s), nor installed any such driver - not even a virtual printer like Adobe Acrobat - on this current installation of Windows 7. In fact I have my Print Spooler service set to Disabled because of this.

I haven't had any problems running and using the full functionality of Word 2003, 2007 and now 2010. In Word 2010 under the Print tab it just says No Printer. Selecting it, or selecting a print function anywhere in Windows takes me to a prompt to set up a printer, which I cancel. So there is no explicit third party printer driver installed on this system, of that I am certain. Hence the bug may even be with the generic Office print device.

@Doug - thanks for the offer, however the documents in question vary and the one causing the problem right now is a 300+ page book which I'm loathe to share. I have however seen it with a shorter document of around 20 pages which I and another person with Word 2007 were editing back and forth recently for a project (again not open for sharing). Every time I'd fix it up and save it in Word 2010, send it to him, he'd note that spaces were being deleted, and either he or I would fix it, and it would occur again. I'll create a brief two-page document, save it and send it to you instead to hopefully demonstrate it.

Right now I've installed Word 2007 alongside Word 2010 and I'm going to play around to see if I can figure precisely what is causing them. This is the first major bug I've run across which I can't really get a decent workaround for. I'd prefer not to have to switch back to Word 2007, but it may be necessary if this bug is not resolved in Word 2010 in one form or another.