Firefox produces unsearchable pdfs
Firefox does not control the way your content is being printed to the PDF. Your PDF Printer Driver is responsible for creating the PDF file as a Bitmap snapshot of your page, instead of composing it from the elements in your page. The reason that you find a different behavior in Chrome compared to Firefox, is that Chrome has a built in "Save as PDF" which is different from your installed PDF drivers. So it really comes down to what PDF Printer Driver you are using.
Currently I'm writing software for web automation using selenium and autoit. 
I've found a strange issue, that for some pages when printing to pdf with firefox I get unsearchable pdfs. I've tried ff 3.5, 4.0, 20, 22, 23 - all have the same issue.
You can reproduce it by printing any linkedin profile - you'll get unsearchable pdf.
Did anyone encounter the same behaviour? How can I bypass it (using python, selenium)?
I've tried chrome driver, but it's increadibly slow.
I'm running windows 7 x64 ultimate
It does not deppend on printer used - I have tried a lot of different versions.
By searchable I mean that I should be able to search text in it like in most pdf files.
Update - I still don't understand why it happens. I've tried printing the same web page from IE 9 - it gives exactly the same print dialog as firefox and uses the same pdf printer driver. Nevertheless, it produces searchable pdfs. Guess the problem is related to the way firefox prints documents.