do NOT use log and transfer. It is buggy as all hell and will only transcode part of your clips, resulting in a mess and confusion and loss of data. Log and transfer, even if it did work, still wouldn’t fix this problem. The reason you are having this problem is probably because the drive you are encoding to is formatted FAT32, which has a maximum file size of around 4GB. So the clips that are short enough to be encoded in the format you want and still be under 4GB are successful, but then the ones that are too long fail as soon as they hit 4GB. Your options are:
Encode to a different hard drive that is formatted something other than FAT32, if you’re using mac that probably means “MAC OS EXTENDED”.
OR
Copy the things you need off of the hard drive you are trying to encode to, go to disk utility, and format it for MAC os extended. Then you can put your things back on it and try the encode again.