Hi haplo4,
I have no clue, but would recommend you to run some malware scans as a start anyway. It is always step one when troubleshooting odd issues.
Try the
MRT first. Then try one or two of
Malwarebytes,
Spybot and
SuperAntispyware. Do not install anything that run memory resident like TeaTime. Then try some
OnLine-scanners.
When you feel confident you are malware free, and this may very well be the case, report back to the forum, and I think someone will be able to help you fix your problem.