Because the player is picky about what specifications it wants in xvid video. You are lucky it plays from the usb connector.
Look at the manual of your player, and find out the exact specifications it needs in divx or xvid files. Then examine the file you have now with MediaInfo and find what it has that your player doesn't like. Warppoints and Qpel are two things to look for, since most stand alone players won't accept that in the encoding.
By the way, dvdrip.xvid.ac3 is a term used for dvds converted to xvid, usually in avi containers, then shared illegally through torrents. If you had included the specific name of this movie, I would have shut this thread down immediately. We do not discuss illegally distributed media on this site.