apply for a new work visa, the original business M type not used yet?

hello mu friends , I got business M type , i was planning to go to china for internship i applied for F type but they gave me M type for one month , anyway i did not use it yet , i am still in my country , but i got a job now in china and they will send me all the required documents to apply for work Z type in my embassy , my question is, is it a trouble to apply for a new entry permit while there is one in my passport not used yet ???