Unable to open MS Spreadsheets using File Association - whats the fix ?

I installed the full Libre Office (4.1) on new mini-pc last December running Windows7 Pro 64-bit.
My method of accessing all document types ever since first using a PC, is to double-click on them, which uses the Filetype Association to launch the Associated App opening the document at the same time, as I found it the most productive way of working.

But when I click on a xls or xlsx now, Libre opens the document in ‘Writer’ which obviously is wrong. I am able to open Calc directly and then use its dialog to open the Excel file, but that is longwinded.

Windows ‘set Default Programs’ >LibreOffice4.1 states ‘This program has 48 out of 65 defaults’, and shows all Microsoft Excel filetypes, set to ‘Current Default’ = ‘LibreOffice Calc’ - so why do Excel files try to use ‘Writer’ ? and how do I fix the problem ?

Maybe you can use additionally or alternatively the settings in LibO:

Tools > Options > Load/Save > Microsoft Office and check all 8 boxes related to Microsoft.

Many thanks for your suggestion. I looked, and found all 8 boxes for MS are already ticked. Do you know if this is a common issue ? If not, I am wondering whether to do a standard uninstall, download afresh to see if that sorts it ? I was a MS Office user for many years, and all 3 Office Apps would automatically open when I clicked on a doc, spreadsheet, or database, so was expecting LO to do same.

Also, might it help if non-MS filetypes can be deselected ?

As its now over a week since my inquiry, does anyone know if lack of spreadsheet filetype association is a common issue ?