Welcome to the forumI to also own a SP4, Having identical issues Plus More, Video TDR Driver bluescreens, Video memory managment bluescreens, ive done all the windows updates, i downloaded the windows SP4 driver package from there site, ive also then done a factory reset and done the same again, STILL THE SAME ISSUES
The device is flawed in so many ways i am unable to do anything from basic word processing to any form of adobe work
Im out of the 30day period but a return is a must for me now, Do you think its still possible?
 Another spontaneous issues, when under 80-95% CPU Load the device cannot maintain a connection to Bluetooth or wifi devices? Even when plugged in running on mains power? Wtf?
Thanks for the quick responce, I've made another more formal post asking for suggestions, but just on the replacementWelcome to the forum
Your SP4 may indeed need replacing. The problems you are having are not any I've seen on quite a few I support. It should still be in warranty from Microsoft.