If you have an "always open", normal broadband connection... don't worry about it. You will see your uploaded stuff on WCG pages... with a delay.
Here's how you can ease your mind. In BOINC client, open the "Messages" tab. Lines like these...
Code:
Thu 05 Feb 2009 11:13:25 EET|World Community Grid|Started upload of faah4784_TL3_MIN3_xMut_md03150_08_0_0
Thu 05 Feb 2009 11:13:25 EET|World Community Grid|Started upload of faah4784_TL3_MIN3_xMut_md03150_08_0_1
Thu 05 Feb 2009 11:13:29 EET|World Community Grid|Finished upload of faah4784_TL3_MIN3_xMut_md03150_08_0_0
Thu 05 Feb 2009 11:13:29 EET|World Community Grid|Started upload of faah4784_TL3_MIN3_xMut_md03150_08_0_2
Thu 05 Feb 2009 11:13:30 EET|World Community Grid|Finished upload of faah4784_TL3_MIN3_xMut_md03150_08_0_1
Thu 05 Feb 2009 11:13:30 EET|World Community Grid|Started upload of faah4784_TL3_MIN3_xMut_md03150_08_0_3
Thu 05 Feb 2009 11:13:32 EET|World Community Grid|Finished upload of faah4784_TL3_MIN3_xMut_md03150_08_0_2
Thu 05 Feb 2009 11:13:32 EET|World Community Grid|Finished upload of faah4784_TL3_MIN3_xMut_md03150_08_0_3
... mean "your" work has been uploaded. Still not convinced? Open the "Transfers" tab. If it's empty, there is no work "left hanging" on your computer.