I don't have Mavericks installed. When you run it in windowed mode does the screen resolution in the virtual machine change when you change the virtual machine window size? If not, then it means the Parallels video driver (part of Parallels Tools for Mac) is not installed. Do other Parallels Tools work such as shared folders?
Code:
Joes-Mac-Pro-VM:~ joevt$ kextstat | grep parallels
39 0 0xffffff7f80974000 0x4000 0x4000 com.parallels.kext.mouse (9.0 23046.917896) <37 26 7 6 5 4 3 1>
62 0 0xffffff7f80b27000 0x8000 0x8000 com.parallels.kext.video (9.0 23046.917896) <61 9 7 5 4 3>
70 0 0xffffff7f80ba3000 0x5000 0x5000 com.parallels.kext.tg (9.0 23046.917896) <9 4 3>
86 0 0xffffff7f80c46000 0x16000 0x16000 com.parallels.filesystems.prlufs (2010.12.28) <7 5 4 3 1>