I have been able to download a couple of videos, but they stop playing part of the way through...one is supposed to be over and hour and it plays for about 5 min and then stops...Also, I can't fast forward or rewind. Is this just a limitation of the file?

Yup, it is indeed. There are several possible reasons behind this. Most likely at somepoint someone canceled a download of that video partway through and then shared it with theworld. That means that that complete hour of video simply isn't there in your file. Many video formats (Most notably asf) Contain and index in the file headers that give the supposed playlength. Although this results in a situation such as yours (note that the mpeg format does not use such a headera subsequently ussualy displays the correct playtime), it also prevents the unfortunate situation with many avi formats (which contain an index at the END of the file) where partial downloads often cannot be played at all without special software to rebuild this index.

Oops, I forgot the other possibilities:
2. There was a transfer error, resulting in ccorrupt data. Some video formats handle this very well (most mpeg codecs do), but some corrupt asf files will kick out when it hits the bad data (it is often possible to skip over these errors by simply fastfowarding past them) and avi files encoded with the divx codec will often have the video freeze while the audio keeps playing (again, this can be resolved by starting the video at a point after the error)

and 3: There is a decency chip built into many video cards today that attempts to detect pornography through excessive use of skin tones. If such skin tones are detected in a single stream of data for a long enough period, the chip will kill the video stream at the hardware level.

As a side not... DIVx is possible to unfreeze without a large amount of getting up and moving the slider bar... simply go to you command prompt and type:

For Win 2000/NT

c:\winnt\system32\regsvr32 /u divx_c32.ax

For Win 95/98/ME

c:\windows\system32\regsvr32 /u divx_c32.ax

To undo this change simply type the above without the "/u"

Please not this taxes your CPU a bit more so people with slower computers/videocards be warned... but the result is nice the movie glitches at the point and you lose a frame of two but both the sound and picture keep on going.

Cool, that's the first time I've ever seen that fix. I think the newer divx codecs coming out of projectmayo are supposed to circumvent this problem altogether