eCommerce 5.2 Cannot create contact in Turkish (Turkey)

Hi all, I got an exception when creating contact in Turkish. Please see my sample code:

private void Add(CustomerContactModel contact, MembershipUser user)
{
var customerEpiserver = Mediachase.Commerce.Customers.CustomerContact.CreateInstance(user);

customerEpiserver.FirstName = contact.Firstname;
customerEpiserver.LastName = contact.Lastname;
customerEpiserver.Email = contact.EmailAddress;

// Assembly: Mediachase.Commerce, Version=5.2.628.0 & Mediachase.BusinessFoundation.Data, Version=2.4.3.0
customerEpiserver.SaveChanges();
//Exception: System.FormatException: Guid should contain 32 digits with 4 dashes (xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx)
}

Debugging I see the exception from "EvaluateGuid" function in Mediachase.BusinessFoundation.Data.Meta.DefaultValue class. The system tried to create default value (new guid) for CreatorId and ModifierId fields, but it failed.Please see the following screen-set for more details: 

You can see "if (string.Compare(field.DefaultValue, "NEWID()", true) == 0)" always return 'false' in Turkish culture (tr-tr). Therefore, line 114 is excuted => exception.

Could you please give me advise to fix this issue in this case (Turkish language - Mediachase.Commerce, Version=5.2.628.0)?

Many Thanks!

P/S: When I decompiled Mediachase.BusinessFoundation.Data, Version=10.8.0.0, I see that EpiServer already fixed this issue by using line of code
if (string.Compare(field.DefaultValue, "NEWID()", StringComparison.InvariantCultureIgnoreCase) == 0)