Having told you about the new version of Spotify Mobile for iPhone just the other day, you might be wondering exactly where to find it in the App Store. Unfortunately, v0.4 has actually been yanked - not at Apple's behest, but by Spotify themselves. Turns out, the new version's iPod integration - which could use locally stored tracks rather than downloading them anew - was causing some issues for certain devices, resulting in crashes. Spotify have sent a new version, v0.4.1, through to Apple, but they're still waiting for it to be approved.
Other users, meanwhile, were finding that their WiFi routers were prompting DNS errors, which resulted in the app hanging forever when trying to login or restore. v0.4.1 will address that, as well as have an option to shut off local iPod integration (with a two minute delay when you first load the app, to give you a chance to head to the settings and shut it off if it's been causing you problems), but now we have to wait until Apple's App Store minions shuffle the paperwork and approve it for release.