Recent findings from research into Computer-Supported Collaborative Learning (CSCL) have indicated that not all learners are able to successfully learn in online collaborative settings. Given that most online settings are characterised by minimal guidance, which require learners to be more autonomous and self-directed, CSCL may provide conditions more conducive to learners comfortable with greater autonomy. Using quasi-experimental research, this paper examines the impact of a redesign of an authentic CSCL environment, based upon principles of Problem-Based Learning, which aimed to provide a more explicit scaffolding of the learning phases for students. It was hypothesised that learners in a redesigned "Optima" environment would reach higher levels of knowledge construction due to clearer scaffolding. Furthermore, it was expected that the redesign would produce a more equal spread in contributions to discourse for learners with different motivational profiles. In a quasi-experimental setting, 143 participants collaborated in an online setting aimed at enhancing their understanding of economics. Using a multi-method approach (Content Analysis, Social Network Analysis, measurement of Academic Motivation), the research results reveal the redesign triggered more equal levels of activity of autonomous and control-oriented learners, but also a decrease in input from the autonomous learners. The main conclusion from this study is that getting the balance between guidance and support right to facilitate both autonomous and control-oriented learners is a delicate complex issue. (Contains 6 tables and 1 figure.)