I haven't tried directly from the browser, which I think is also a beta feature. If it's important to you, I'd be happy to give it a try. Exporting acsm into an EPUB with Adobe Digital Editions and then synchronising it on the device using calibre works perfectly, of course. Ideally, convert it to a KEPUB with calibre, then you can also scroll very smoothly and set additional reading options (font, spacing, etc.). Hope this helps :)