I am afraid this problem still persists for me. I have i386 Ubuntu 10.10 on Win7 64-bit. This was originally Ubuntu 10.04, so I upgraded vbox first, and then upgraded Ubuntu via the update manager. I had trouble uninstalling the old guest additions and installing the new ones, but I was finally successful. I did not use the Maverick packages -- Installed from the ISO provided with PUEL.
At first, it was crashing literally every 10 minutes, but it's gotten a lot better after I installed the new Linux kernel (sudo apt-get install linux-image-2.6.35-22-generic). I haven't used it long enough to gauge how much better, but it is definitely a problem. First, it becomes slow at responding to keyboard and mouse strokes, and then within a minute it freezes completely and requires a hard restart. It's almost as if there is a memory leak somewhere.
Another related problem is that after I do a hard-restart of my computer because of this, it sometimes refuses to recognize extra display resolutions that guest additions provide. Sometimes this problem is resolved with one more restart, other times I have to uninstall and reinstall guest additions.
I suspect that my installation is "dirty" because I upgraded, and this is causing problems. I thought that this is because I installed and unskillfully removed the guest additions so many times, but now when I remove it and then search my computer for vbox* files, it only comes up with logs. I'll try a clean install of 10.10 as a new VM, but the VM I am using now is a production machine, and it will take me a lot of time to migrate to a new VM.
Is anyone else still having these problems? Could someone suggest settings I could check to make it work better on my end?