Today I decided to upgrade to the latest version (188.8.131.523) of Malwarebytes Antimalware from 1.75 (Vista SP2 32bit). Uninstalled the old one using mbam-clean.exe, restarted. No problem so far. Then I installed MBAM.
Unfortunately the MBAM icon in startup menu wasn't shown up correctly. I tried to change/repair this shortcut icon. No success. So I restarted my computer again. This time the start menu was completely blank and very sluggish. Restarted with sheduled sfc one more time. The start menu came back working as expected. But the MBAM icon was still wrong. After a few tryings (to change icon) I was able to get the correct one.
There is no problem anymore. However, I just wanted to ask you what could be the cause of this behaviour.