When my monitor comes out of standby the mouse pointer is missing. Mouse appears to work OK (if you can work out where it is!) but clicking on exit does not close Boinc Manager. The only way to get mouse pointer back is to click "Show Graphics" all is then OK till monitor goes to standby again.

Some additional information would be good.
What operating system do you use?
Is it up to a recent patch level (WindowsUpdates or Mac Software Update)?
How much memory do you have?

Just assuming you use windows, I would suggest three things. Disable / turn off BOINC while doing these. Actually, you'll have to reboot a few times, so close everything you can.

[1] Assuming you are using Windows, go to Microsoft.com and do a search for DirectX. Actually, the runtime installer link is below, but I don't know if web links will be edited out of my post.

http://www.microsoft.com/downloads/details.aspx?FamilyId=2DA43D38-DB71-4C1B-BC6A-9B6652CD92A3&displaylang=en

Go to this link with IE, as the Microsoft Validation Tool works better as an ActiveX plug-in for IE. (You can do an off-line validation, but it's more time consuming.) Download and install the latest DirectX client.

I read somewhere that with BOINC 5.8 the screen savers can have odd behavior with old DirectX clients. This alone could fix it, but it has a chance of breaking some old (4+ years) games.

[2] Go to the web site of the manufacturer of your mouse, if it is a major brand (Logitech or such), and download & install the latest mouse drivers.

[3] Open IE again. Go to "Tools" in the toolbar, then "Windows Update". Select "Custom", not "Express". This will show you all available updates, not just the emergency patches. Look at the hardware driver updates (categories on the left), and add those to what you download. (Note that if you add video drivers, it may re-scale your resolution to the minimum or maximum allowed when you reboot. This is normal. Don't panic, just set it back.)