Mine does also. Took it to a repair shop, got charged 40 dollars, brought it home, plaued a tape for 30 minutes and nothing 'stopping' happened...but then when I re-hooked it up, same problem happened again after a while (but the recipt says "30 day warrenty"). It will record or play for any amount of time (gets shorter and shorter) then it stops, then when you push power, the tape ejects, and the words appear on a screen "EJECT ^ R". I am taking it back to them, photocopying recipts.
M.p.h., November 2008