Malwarebytes didn't find anything, but the fact that you don't experience this problem when in Safe Mode leads me to question if this is a Service or Startup item causing this. To find out I would like for you to run a Clean Boot.
***This is a diagnotic tool for Windows Vista, Windows 7, and Windows 8. This will not repair your computer, but it may point to where the problem lies so that a repair can be made.***
Warning: Disabling items in Services or Startup may leave your anitivius disabled until the process is ended. For this reason I would suggest that you perform this process off line.
(1) Click on the Start orb, then type msconfig.exe in the Search programs and files box.
(2) When msconfig is seen in the pane above the search box and under Programs, right click on it, then click on Run as administrator.
If you are prompted for an administrator password or for confirmation, you should enter the password or provide confirmation.
(1) Click on the General tab.
(2) Click the Selective startup option.
(3) Remove the check mark in the Load startup items check box.
(1) Click on the Services tab.
(2) Place a check mark in the Hide all Microsoft services check box, this will remove the Microsoft Services from the list but will still be running.
(3) Click Disable all, this will remove all of the check marks in the Services list, then click on Apply, then OK. Click on Restart in the window that opens.
Caution: I repeat, by disabling the Services your antivirus will not be active, for this reason I suggest that this process not be run while online.
If the problem does not reoccur after the reboot this means that there is a Service which is causing this proble, continue with the process of elemination to find the Service which is causing this in Option A. If the problem does reoccur after the reboot go to Option B.
**The following is a process of elimination to find the Service or Startup item that is causing your problem**.
* If the problem does not reoccur after the restart go back to Services and place check marks in half of the boxes and restart the computer.
* If the problem still does not continue return to Services and remove the check marks that were added, then place check marks in the remaining half of the boxes and restart the computer.
If the problem resumes after a restart in one of these halves, you will procede with this process in the half where the problem occurs. If this does not continue in either half you should repeat this process in Sartup.
* In the half of the Services that the problem is found, remove one check mark at a time and restart the computer to see if that is the Service causing the problem. Continue to do this with the Services untill the service causing this problem is found.
Search Startup itmesIf the problem is not found in Services, remove all of the check marks, click on the Startup tab and repeat the search process there.
Caution: If this is a laptop, make sure, you do NOT disable any keyboard, or touchpad entries.
If this problem is found post the Service or Startup item that is causing it.
When you are finished using the Clean Boot go back to System Configuration and click on the General, then click on Normal Startup, click on [b]OK, then restart your computer.