What makes you think the completed work unit wasn't uploaded? Before downloading a new work unit, it ALWAYS uploads the results of the previous work unit, whether that work unit successfully completed or ended in some sort of error.

Also remember that work units can vary greatly in how long each takes to complete, so just because you had one complete in 4 hours, doesn't mean the one taking 2 days is "bad". It just means it's harder to predict the proper fold.

What makes me think it was lost are:

1) when the work unit finished, there was no message indicating the resultes were uploaded. This might be an incorrect assumption based on my observation of such of message from other UD grid clients.

2) The work unit does not show up in the completed work information on the web page 2 days after it completed.

3) No points were creditied for the work.

4) The program asking me to log in and the download of the 4Mb task before a new work unit was aquired.

Now these points are from my observation as an end user. It could well be the results were uploaded, and I really do hope they were. But the program from my perspective is after doing all the work, it appears the results were lost.

I again had another work unit "disappear" last night. The one thing in common I have noticed with the two lost units is the internet connection was not up at the time the work was completed. There may be a problem with getting finished work upload after a connection is made if the connection was down at the time the work was finished.

I guess I've lost about three hours.
I had my WCG running for almost 2 hour (2%; 4Mbyte work unit) during an Internet connection and then I went off-line.
The program continued to work, but when I came back to the PC I had to notice that the program asked for an Internet connection and that the results of the work were zeroed.
When on-line the program downloaded another work unit (1 Mbyte) and started again.
How can I know what's happening?

If you do not have a permanant connection to the internet and you closed down your connection while a work unit completed it will suspend all action until you re initiate a net connection so make sure you are connected to the internet then Double Click on the system tray icon for the World Comunity Grid Agent and it will connect and upload your completed work unit and download another unit automatically
Hope this info helps