It doesn't matter where I go, I always run into people having printing issues with Flex. Most have found the FlexPrintJob class and samples on how to use it, but for those who print multiple pages the results are sometime less than stellar.
I just found a new open source project called FlexReport. Apparently, this guy has had the same problems as others. You should check it out if the idea of "Print Preview" sounds good to you.
Here's the pdf generation tool behind FlexReport. I've worked with both in trying to generate a pdf client proposal from data. I found it easier to manipulate the document with this: http://www.alivepdf.org. However, if rather than a letter you require embedding a table of data, probably best to start with FlexReport. Oh and if you find a problem, try logging it and then see if you can beat the author to a fix. Thibault won't give you much of a chance...
If you are able to use AIR for the client, you can offer a preview option without using FlexReport - simply drop the pdf on the desktop (no round-trip to the server to have php generate the pdf - Astro will fix this situation also) and then let AIR open it using navigateToURL(new URLRequest( file.url )). It comes up in a browser window with the embedded PDF.
Both projects could use some serious investment to allow an end user to create reports dynamically and directly from inside a Flex or AIR application. Also FlexReport seems to have some problems with an extra blank page getting printed and from my testing there's pdf quality issues as well (final print looks poor on paper as if it is a scaled image).
Anybody know what is used in industry (perhaps non-open source)? I would think most business clients would want a completely drag and drop style report generator that makes it child's play to lay out the report and bind it with data as well as export to other formats such as XLS (Excel).