I skimmed the posts and I couldn't see any mention of filesystem type for the external/2nd hard drives
Do we know what it is ? the external drive sounds like it may be behaving as if it is NTFS. In which case he needs to install ntfs-config and its dependencies and then run sudo ntfs-config and check the options to enable write access.
A copy of the output of tail -f /var/log/messages as the external drive is plugged in may help here.
So, instead of the "/dev/hda1" etc. that I'm used to, there's a huge "UUID=...." identifier for the "hda" device, which is different according to each partition on the device.
This is the new way :)
It's better because the UUID is of course unique to each volume which means that there is no chance of drives being mounted in the wrong places if something causes device nodes to reshuffle (happens a lot to those with advanced docking stations on laptops that include a drive bay) With UUID's you could literally swap master/slave jumpers about etc and still have a working computer.
To get the UUID in the first place you run 'sudo vol_id /dev/hdb1' Then insert this in your new line in fstab as per the others.
Although just because some volumes are using UUID in fstab doesn't mean that they all have to..you are still free to add device nodes as before. However I recommend he take the 5 mins extra effort to do it with UUID.
By the way another cool thing you can do is set Labels (e2label for ext partitions) and then define your disks by Label=blah rather than using UUID's or device nodes.