Here are the steps I take to reproduce the crash.
select Patient-> [some patient1]
Select module images
Double click to open image (starts associated external program)
Reviewed and closed program (ie closed adobe acrobat reader)
Clicked on chart module
opened new patient [somepatient2]
clicked on images module
error occurs (Unhandled Exeption)

Our Images are are a networked and lettered drive. Drive access and rights is not the issue.
Here is the code/stack trace (okay I know it's not a real stack trace but you'all have seen this before)
Sincerely,
Dr. Krueger
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************** Exception Text **************
System.Runtime.InteropServices.COMException (0x80004005): Error HRESULT E_FAIL has been returned from a call to a COM component.
at System.Windows.Forms.UnsafeNativeMethods.CoCreateInstance(Guid& clsid, Object punkOuter, Int32 context, Guid& iid)
at System.Windows.Forms.AxHost.CreateWithLicense(String license, Guid clsid)
at System.Windows.Forms.AxHost.CreateInstanceCore(Guid clsid)
at System.Windows.Forms.AxHost.CreateInstance()
at System.Windows.Forms.AxHost.GetOcxCreate()