Processor frequency and DirectSound on Windows XP 64 Guest

[thesourcehim]

My primary OS is Fedora 11 x86_64 and I have VirtualBox 2.2.4 x86_64 installed. I'm using Windows XP 64 as guest OS and I have the following problems:
1. My CPU is Core 2 Duo P8600 2.4 GHz, but guest OS detects CPU differently each time it boots. Resulting frequency is completely random (I even saw > 100000 GHz!). This creates certain problems, like super-slow fading menus.
2. Sound is usually fine (I use alsa driver - VirtualBox with PulseAudio creates glitches - my card is Intel HDA), but when it is used via DirectSound (Heroes of might and magic 3 for example), sound samples start to repeat many times before playing next sample (I call it 'sound hickups').

Has anyone encountered similar problems? Is this VirtualBox bug or am I doing something wrong?