Something really weird has been happening the last few days. I use Windows XP Home Edition.
Whenever I right-click to get the context menu in some of my applications, it comes up invisible. It only becomes visible as I move the mouse cursor down the list. This isn’t happening with Firefox or Thunderbird, but is happening with my native Windows XP folders, WinMX and WinAmp.
What could be causing this and what can I do to fix it?
Might be a bad context menu handler. Download and run ShellExView, which shows all Windows Shell extensions which are installed. Look for the context menu handlers (you can sort them by type by clicking the appropriate column header) and disable them one by one until the problem goes away. Once you find it, you can enable the other ones you disabled and leave the faulty one disabled.
I get this often too. In my case, it tends to happen when my computer runs low on RAM, generally because of IE’s stupid memory leaks that occur if too many windows/tabs are open.