Work permit cancelled/residence permit still valid

Hi, I'll be leaving my company next month, and moving to a new company. My residence permit is still valid for another three months, but my current company will cancel my existing work permit and give me a release letter to change it to my new company. However, a few weeks after my work permit is cancelled - and before my new company are able to process the transfer - I need to go in and out of China. I am told that it won't be a problem going in and out of the country on my current residence permit. I was told this by the visa agent processing my transfer, and they are one of the biggest in Beijing. But I keep reading that once my current company cancels my work permit, although the residence permit is still valid, it's technically not. Everybody contradicts one another. I'd like to believe the agency as they must deal with this kind of thing all the time. Do you have a solid answer on this issue. I don't want to leave the country and be told my residence permit isn't valid anymore.