Outlook shortcuts and executable icons will not open Outlook

Vista Business 32-bit SP2. Outlook 2007 (though the problem started with 2003 and upgrading didn't resolve it).

When I click on Outlook shortcuts or even the Outlook executable in Program Files, nothing happens. The ONLY way to open Outlook is to go to run and type outlook /recycle and enter and then it opens and functions normally. Typing outlook or outlook.exe alone without the switch does nothing. I don't remember how I discovered the switch when it first occurred (over a year ago) and I don't know how or why it works (thankfully it does) but I'm tired of having to open Outlook this way.

Adding /recycle to the target in the shortcut results in an error message "unrecognized switch" - even though it works and is recognized in run. I can see no way to amend the shortcuts to include the switch other than to alter the target and that creates the error message (which means the icon is at least working to some degree - though this doesn't explain why the actual outlook.exe program executable file doesn't work either). Why in heaven's name is this switch necessary? This is even true in the Quick Launch icon which my other systems have /recycle included (as I understand this is normal in that situation) but it isn't on this system and if I add it I get the error message.

Repair makes no difference.

Uninstalling and re-installing Outlook (even the entire Office Suite (Enterprise) makes no difference.

Creating new shortcurts makes no difference.

Scanned with Malwarebytes, Microsoft Malicious Software Tool, Pandasoft, MSE, OneCare, Avast and HijackMe - nothing significant (a few tracking cookies) detected. MSE is normal software with Malwarebytes run about monthly or so. Never had a major infection that wasn't caught and removed by my AV program. All other software removed properly after testing with removal tools where applicable - never had more than one installed at the same time (except Malwarebytes which I never removed once installed but have set to scan only on command) - so I didn't mess things up with multiple versions simultaneously installed or improperly removed.

SFC /scannow comes up no integrity violations found. Chkdsk /f /r comes up clean. Problem occurs in Safe Mode with Networking and in Clean Mode.

What is /recycle (I mean, what does it do exactly) and why does that work in run but not in a shortcut? Why is it necessary at all (it isn't on any of my other computers)? How do i get shortcuts to work (or even the program executable file itself - with or without the switch - I'd prefer without but will settle for with if it can be made to work with the icons)? Is there some entry in the registry causing this - that's my guess (I'm a systems engineer and comfortable with the registry but can find nothing to change to resolve the problem or even that seems related to the problem - and I've looked several times)?

I'm open to suggestions. I'd really like to know what /recycle does and why that makes it work (and is the only thing that makes it work).

Thanks in advance for your assistance. If I can provide any additional information, just ask.