Did you notice that the file generated from write.table() in R has missed a tab (\t) in the top-left corner, when row.names=T (by default)?
I found the solution here:
col.names = NA,
row.names = TRUE)
Actually, the R document has stated it clearly:
By default there is no column name for a column of row names. If
col.names = NAand
row.names = TRUEa blank column name is added, which is the convention used for CSV files to be read by spreadsheets.