hi there,
you only need an app like Google Docs or Apple Numbers, if you want to edit an Excel file on your iDevice. Read-Only access (Preview) should work from within the email app itself.
So, since it apparently works on some iDevices and not on others, pinpointing the culprit gets a little more difficult.
A few possible starting points:
- Does the problem occur with all Excel files? If not, are there any complex features (e.g. macros or diagrams) inside those Excel files that do not work?
- Are they created from within MS Excel itself or from within a 3rd party program such as OpenOffice using the "Save As..." dialogue?
- If created with Excel, which version of Excel is used to create those files?
- Also, try to open those Excel files directly after rebooting your iDevice or after clearing the "recently used app" list, as there might be a problem with insufficent memory due to too many open apps.
Hope this helps,
Chris