On all the e-readers I've seen and owned, reading IT-books is cumbersome, if not impossible.
This is mostly because of the formatting of example-code in the books (epub and PDF).
PDF books work, somehow, but only when the text is not enlarged: as soon as the ebook-device starts re-flowing the text in the PDF, code formatting breaks horribly.
Epub code-formatting seems to never really render properly. This appears to be caused by re-flowing and by often removing spaces (indentation).
What devises renders code nicely? I am not looking for coloured syntax highlighting. But mostly a rendering that retains the indentation, renders in a mono-space font, and avoids re-flowing of text in code-blocks.
My Sony PRS-T1 does a great job with PRE tags, but I've never tried to read a technical document on it so I can't offer any more than that. If spacing is done properly using CSS or tables it renders it perfectly, but if you try to indent using a bunch of spaces then it will do what it's supposed to and only display one of them (remember that epubs are basically Websites, and render accordingly). I'm well acquainted with spacing from making epub character sheets for various roleplaying games. That's also how I learned my T1 renders PRE properly, but the current versions use tables and again render perfectly on my T1, as well as my wife's Nook Simple Touch.
That tells me that the display problems you're seeing are as likely to be from how the document is coded as from how the device renders them.