Are you using the latest Servce Release 7.3 or the latest Service Release Candidate 7.4? The last message in the thread I linked to said the problem appears to be solved in Service Release Candidate 7.4.
A new Service Release Candidates is released on most Tueadays: Rhino 7 Service Release Candidate Available - #12 by brian
A new Service Release is released about once a month, usually on a Tuesday. Rhino 7 Service Release Available - #6 by brian