Another common quirk I've found with reflowed pdf's is unexpected page breaks. In a pdf file, the page breaks are hard coded in, so when the document is "reflowed" it can sometimes have page breaks where you really wouldn't expect one.
Not the end of the world--especially when you don't have to pay for the book!
I'm hoping that more libraries will start to follow the Cleveland library's example and offer E-Pub files for download, as these work well on the Sony Reader!
dordale