When I connect my Nexus S to my computer I can see various files (media, LOST.DIR, DCIM...). If I copy a file here, I can't find it on the file manager (ASTRO) on my phone? How do I access these files on my phone?
Make sure you've disconnected from the computer and the phone has remounted the card, then navigate to
/mnt/sdcard/. (On other Samsung phones like the Galaxy S, you would go to