where is the method 'GetMessageUidsWithNumber'

[zousq19910623]

i use the openpop Version=2.0.2.340
when i invoke Pop3Client.GetMessageUidsWithNumber
i throw exception '[FormatException: 输入字符串的格式不正确。] System.Number.StringToNumber' and so on..

but i can't find this method 'GetMessageUidsWithNumber' in source code.

so what kind of problem will cause this error..??

pls help. online waiting