the max input and max execution time settings are in seconds. your settings:
max_input_time-60
max_execution_time-30
will have the script time out after 30 seconds. If it takes longer than 30 seconds to upload the file, it will time out, I suspect this is the problem.
the max input time of 60 seconds will also cause issues if it takes longer than 60 seconds for the client to transfer the file to the server.