dynamic dll load using reflection

My app contains a module that dynamically loads dlls via reflection. When i load simple dlls everything works perfectly. The problem arises when i try to call a method inside a dll(A) that references another dll(B). For example, dll A references dll B, i reflection-load dll A and call a method that requires dll B. dll B is in the execution path of the application and there are no exceptions being thrown. when i debug and step in the lines, the method call is skipped(or so it seems) and nothing happens. when i force a step in i get a screen saying "Code not running". i tried to put the .cs files in the same folder that dll A is and then it worked. now why would it require the .cs files? how can i make this work?