My Salesforce IDE is overwriting event's changes - even files I haven't changed


Hi guys,
in the past few days I’ve had a problem where my C9 Salesforce IDE has started overwriting files on the SalesForce Org with the ones on my system - even if I haven’t changed them. This has overwritten work by other team members and resulted in a loss of work.

I can’t risk using the IDE again until I am certain this issue is resolved.

Please can you investigate / resolve asap?
Many thanks,