Sorry, for the confusion here. If you want to divide EARNWEEK by a measure of usual hours worked, you should use UHRSWORKORG. Similar to the EARNWEEK variable, this variable is part of the outgoing rotation group of questions. The UHRSWORK1 variable, by contrast, comes from the basic monthly survey set of questions and presents some computational challenges when applied with the EARNWEEK variable. You can read more about the outgoing rotation group here.
The general rule of thumb when applying sampling weights that each calculation should only include one sampling weight. This is because some questions only apply to specific respondents and the sampling weight takes care of this complexity.
Therefore you should be doing something like this: [EARNWEEK] / [UHRSWORKORG] * [EARNWT]