Your Humax is doing exactly the same playing files from the USB as mine is from the Hard Drive.
Sounds like a "firmware" issue with the unit. It seems to have decided to add all items in the folder to a playlist, but then misses the last bits.
If we could turn off the playlist, that...
Sounds like Danny is experiencing the same issue as we are and for us it affects every file type we play from the hard drive.
If we are watching the last file in a folder on the hard drive, we get the same 20/30 seconds of lost video and warning triangle with the message "not supported format"...
Now that the technical information regarding the file is available (including size to the last Byte), why do we think the Humax insists on playing the next file before this one is finished?
To be honest if it didn't automatically play the next file it would be better.