With the current version of the .NET SDK (1.0.31) the following code:
Company company = new Company();
company.name = "company_name";
company.company_id = "company_id";
company.created_at = ConvertDateTimeToUnixTimestamp(DateTime.UtcNow);
company.industry = "industry_name";
companyClient.Create(company);
Doesn't correctly set the "created_at" and "industry" properties on the company.
Even when calling update to that company those properties doesn't get set.