AVG 8.0 Free and Microsoft Visual C++2005 Redistributable

I have downloaded AVG 8.0 Free Edition and see that it puts in Microsoft
Visual C++ 2005 Redistributable into the add remove panel. I also see though
that Microsoft have a download for Microsoft Visual C++ 2008 Redistributable
so why haven't AVG used that instead?

Just lately I have been getting a popup box to do with Microsoft Visual C++
2005 Redistributable and have options of ignore, abort, cancel. If I
uninstall Microsoft Visual C++ 2005 Redistributable from add remove programs
panel I see that AVG no longer works and you have to uninstall AVG 8.0 Free
and re-install it all over again.

My operating system is Windows XP home by the way.

Andy.