Total Posts: 41
Go to the backend. In the middle of the footer you can find the version-number. In my case it is “Magento Version 1.0.19870.4”
There was a bug several months ago. As soon as you removed products from the compare-panel in the frontend the whole product was removed from the database. Sounds like you fall into this bug - at least I hope for all of us.
Please keep the community informed since this is very important.