Many stacks that use Javascript to generate their content will need to be “visible” on page load, that is that may not work in things like tabs, light boxes and tooltips that are hidden with the page loads. The reason is usually that they need to know the size of their container element in order to generate the content. If it is not visible then the browser will report a size of zero or an incorrect size and the content will not be generated and sized correctly.
In the non RW world, we would simply trigger a recalculation when the tooltip / tab / lightbox etc opens and has a real size.
With stacks from different developers this is not always possible.
So, to a possible solution. It may well work by using Limelight instead of Popdrop. You can still launch Limelight from your Dossier button (just give it a CSS class of the limelight content unique ID that you set in the settings).
The crucial difference with Limelight is that it has a lazy preload setting. If you turn this on it may mean that the Pagelit calculates its size on page load as normal. This is by no means guaranteed as I don’t have that stack to try it but it will certainly be your best bet for a quick and easy first thing to try.