I have a similar problem, this is my story:
I downloaded a large file from my computer at work, around 650mb. I want to take the download home so, I transfered to my "ACOM DATA" 80gb external hard drive USB2.
The computer at work is only USB1 so it took a good half an hour but it transfer the files as expected.
Finaly I conected the external drive to my home computer (USB2 by the way) which would have take like a minute or two to download, it stops with the same error as "delayed write error and that the data could be lost". I get is this error message transfering the large portion of the download. It was able to transfer small files, but it does not want to work with the big files 600mb. All kind of probles as you guys describe.
So I was asumming that the data was corrupted. Went to work and try to move the files from my external to my work computer, expecting to repeat the same problem, but to the contrary, it transfer the files without any problems!???
I do have XP on the two computers, NTSF on all the drives mentioned.
I think that there is something maybe interfering with my file transfer on my home computer, the fire wall (which I try to turn off to see if that was the problem), or another program that I can't identify, (I will try to use a diferent USB prt to see if it makes a diference) since at my work computer I do not have any problem transfering back and forth to my external hard drive.
I am not sure if this started happening since I installed the service pack2 on my home pc, since I never transfer nothing really big until now.
I am also stumped, but I will find a way. Will let you know.