Hi all,
I had exactly the same problem(s) on my rig at home and also my colleague and I had this problem on our PC's at the office.
Few weeks ago I found out that the problem was caused by a faulty nVidia graphics driver.
After re-installing it back to nVidia driver version 306.97 the problem was completely gone!

Yesterday evening I found out that the cursor problem was back again.
WTF??? Turns out that a Windows 8.1 update was the Trojan horse for the latest nVidia driver update (v.331.82) .

Tonight I will go back to v.314.22. That seems to be the last problem free driver nVidia produced. We'll see...
This is what I found this morning:
http://surveys.nvidia.com/index.jsp?pi=241032f7eb7c9be2b568cb64e9dc9851
So, the problem seems to be well known...
btw. Also watch your HDD led when the screen freezes and/or your cursor changes shape! My guess is that there are very large dump files being written at that moment.
Hope this helps? Let me know...
Cheers!
😉
Sxinner