version 0.11 issues with to_csv
It looks like that some changes were made to the DataFrame.to_csv method, as mentioned in the what's new document. 

Today I found two issues with the updated to_csv:

1) I have an int column, when I use floatformat parameter, the int are changed to float
2) cols parameter simply changes the name of columns, it does not reorder the data in a whole column. 

Thanks for your hard working. Hope we can make pandas less buggy and more powerful! 
