LibreOffice eventually "not responding"

I’ve searched unsuccessfully for an answer to this issue, so I’ll be grateful for any assistance.

We have two Windows 7 Pro, SP1, 64-bit desktop computers running LO LO starts normally and usually works well (Writer and Calc) for a while, but at some point decides that it is “not responding.” We’ve tried waiting a long time, but it never becomes responsive again. Eventually we have to use Windows Task Manager to kill LO, after which we restart LO and hope that it will be able to recover our documents and spreadsheets (usually it does).

This issue is not unique to LO It has existed in at least the last two or three LO versions we used and each time we updated LO to what was billed as the new “more stable” version, we hoped that that new stability would include a fix for this issue, but the issue has persisted.

Any thoughts or suggestions on how to resolve this ongoing problem will be hugely appreciated. Thanks in advance for any and all help.