Problem viewing DVD's in DVD Player

Hi,
I didn't know where to post my question, so I put it here. (Mods please move to appropriate forum if you like.)
Some friends have lent us DVD's. We can watch some of the movies. On others (format VCD) I have to click around a few boxes and then I will get SVCD and it will play. The problem is when we view the second DVD it cuts the movie off about 5 minutes before the end! We tried turning off the power and then inserting the 2nd DVD but it still cut off the end.
We bought another DVD player (Apex was recommended) and installed it today. Well, when we put the disk in marked VCD the player first went into loading and then said "no disc"! We tried a disc that we bought and it played without a problem.
Any thoughts on what is going on here. Other people can view these movies on their home DVD players.
Also, in looking at the paperwork for both players the one that cuts off the end says it is compatible for VCD, etc. but the second that says "no disc" doesn't show VCD.
Thanks for any help.
Sincerely, Nancee