I know there have been some problems with the Teatimer…
why use SpyBot when you have program like Malwarebytes antimalware that is way ahead in detection and ability to remove difficult malware !!!
also see Superantispyware
To answer your question, Avast doesn’t interfere with me updating SpyBot Search & Destroy. Make sure that you have the latest version of SpyBot S&D. FWIW, I use it’s immunize functions without issue and have never encountered a conflict between Avast, SpyBot S&D nor any of the other programs listed in my signature.