Hi,
I have boinc running several projects.
about 1 out of every 5 times it will not give back the pc when I move the mouse or keyboard after it has gone into screen saver.
This is windows XP pro version 2002 service pack 3, intel pentium 4 cpu 2.40 ghz, 1 g ram, 128 ddr ati radeon 9700 tx w/tv-out

Which version of BOINC?
BOINC screensaver or Windows?
Is boinctray.exe running? (Use Windows Task Manager - Ctrl + Alt + Delete to see).

This program is what detects keyboard / mouse movements.

Hi,
The latest version 6.10.58.
When I move the mouse the cursor is moving over the boinc screen saver (which is sometimes still running), but I cannot see the desktop, I cannot use ctrl-alt-del it will not bring up the task manager. I cannot see the tool tray.

I do not understand your question -
BOINC screensaver or Windows? I installed Boinc to be the screen saver, I do not start it manually unless there is some setting I should check.

Then you'll need to look for boinctray.exe BEFORE the screensaver starts.
This program stays in memory, and is used to detect user activity.