the vinagre window will steal my keyboard and mouse, but any keyboard input, other than things like tab, or F12, or enter, will not be shown. I cannot enter a password during installation, I cannot use the arrow keys at a syslinux boot prompt (qemu vnc), etc...
For sake of reproducing this accurately can you tell me what VNC server you're pointing to. Is it QEMU's VNC server, or are you running QEMU with its SDL graphics and then pointing Vinagre to Anaconda's builtin VNC server ? If the latter what distro are you installing ?
QEMU's VNC server. For completeness, rawhide was being installed from 20070905.
Is this still a problem?
Intermittent, and it may be due to my window manager. Sometimes it stops taking some input, like space bars and letters, but will take enter. Sometimes I get double mouse pointers too. Often it's enough to break out (<ctrl><alt>) and change desktops/change back. I don't really have a good way of triggering it, so I'll keep an eye out for any commonalities.