求助：140 needs additional review

My I140 (EB-1A) was filed in 12/2007 to Texas Center. The case passed the processing dates for 7 months.

I called them in January, 2009 and they said my case was actively being processed and need additional review so it takes a longer time. One month ago I went to infopass and I was told that my case has not been assigned to any officer.

Today I went to infopass again and the officer told me the same thing as when I called them,"my case was actively being processed and need additional review so it takes a longer time.". Does anyone have the same experience? Could anyone tell me what additional review is about? Does anyone know whether it helps to write a letter to Senator or Congressman?