Error importing contacts without "Last name" and with a second-level domain in e-mail address

When importing contacts from a comma-separated values CSV file, If imported contact hasn't "Last name" and his e-mail is like test@yahoo.co.uk, CiviCRM displays the next error message:

"67","Missing required fields: Last Name OR Email Address","435","","John","","","","","c/ Test, 6 3-C","","","28000","","Madrid","Spain","Test","","699000000","","test@yahoo.co.uk","","","","1/1/1967 0:00:00","01234567V","21/12/2007 0:00:00","","John","0","BANK OPEN ","0123","0000","00","01234567890","","","","",""

The imported contact has a valid email address, but CiviCRM seems to ignore it. I believe there is a problem with dots from second-level domain.