So MS Office 2013 Preview (Excel) freezes my machine

I run MS Office 2013 Preview on my 17" MacBookPro running Windows 7 Professional SP1 over BootCamp. Every now and then, when Excel is my active programme, my computer freezes over. The mouse becomes utterly laggy and the keyboard doesn't work if I try to switch to another app. The task manager doesn't show that Office has taken over the CPU or the memory. As a matter of fact, shows a relatively free CPU during this frozen state.

Is this a known issue? Does anyone else see this?

I have sent feedback about this and checked if I have got the latest updates. Not sure what is wrong. I haven't yet seen this issue when I use Word, OneNote or PowerPoint. It only happens when I'm on Excel.

Help would be appreciated.