Gentoo Emerge/Compile slowdowns

Ok, im not entirelly sure what it is I did, but somehow I have made my computer basically unusable when doing a compile or an ebuild. I used to be able to listen to music and browse through directories, do 2 or 3 compiles at a time, etc etc, while emerging or compiling something. Not anymore. Now, XMMS will just freeze up, I have to force it to quit. When I try to su, it takes 1min + to verify my password. I cant even attempt multiple compiles, because the computer becomes even worse. I dont know what to do, short of reinstalling Gentoo completely, but really dont want to do that. Does anybody have any recommendations?

Edit 1: Also, it seems things are bringing theirself back. I unmerged Mozilla the first day, and emerged Firefox. Today, I start my computer and boot up firefox, and it says that its not the default browser. Look in the Internet menu, and what do I see? A nice red Mozilla link.

Edit 2: Now looking more, it seems there are things that I did not emerge. Gnome burning utility? I havent gotten anything for burning yet, and I know that link was not there yesterday.

If anybody can provide insight into this, it would be nice, but im going to just start reinstalling right now.

when running a compile run "top" from a console see what process is using the CPU/RAM. If all your RAM is used up and the OS is swapping that will slow the system way down.

Unlikely. 1GB of RAM, plus 512MB of swap.

For a quick fix, try "nicing" the emerge process (eg nice -n 19 emerge package).

Thanks for the information guys. Thought it might be informative for everybody to know, no longer is an ebuild required to get the 2.6.11 sources. Just doing a Gentoo install, and as always, I do emerge gentoo-dev-sources, and suprised to find 2.6.11-gentoo-r4