I've been reading some PDFs on my PRS900, but the problem with PDFs in general on a screen this size is that the text is often small. If I want to read something of any length, which doesn't reflow passably well (straight text does OK), then I convert into another format. Sideways-on is OK, but there are too many page turns for my liking reading a third of a page at a time.
I found that synching with the reader took forever and I can't access the Sony store from the UK - so I'm using calibre. Hopefully, I can't get this bug then (fingers crossed!)