I have installed Ubuntu 13.10 on VirtualBox 4.3.6, running on Windows 7. I have installed the VirtualBox Guest Additions on Ubuntu.
I have used this .deb file to install
If you are starting from a desktop shortcut you can edit the .desktop file's Exec line to be something like Exec=env UBUNTU_MENUPROXY=0 /usr/bin/sublime-text
Exec=env UBUNTU_MENUPROXY=0 /usr/bin/sublime-text
See here for an example of how a similar problem was solved for eclipse.