Contact Last Name attribute limitations?

Hi everyone,

I have increased the maximum length of last name attribute in Contact to 210.

Upon creating a new contact with last name greater than 150 symbols I get a generic SQL error. I tried tracing and the actual error is "Crm Exception: Message: Generic SQL error., ErrorCode: -2147204784, InnerException: System.Data.SqlClient.SqlException (0x80131904): Operation failed. The index entry of length 948 bytes for the index 'ndx_ContactCover' exceeds the maximum length of 900 bytes."

Is there any way to overcome this limitation?

Thank you in advance :)