
To be more specific, the lawsuit points at the PortalPlayer media chips that the iPods use to Decode MP3 and WMA files. Since Apple intentionally turns off the WMA encoding on these chips due to the fact that they refuse to pay Microsoft's licensing fees, the complaint states that Apple is crippling her system intentionally. The complaint goes on further to state that Apple is abusing their market share by only playing music that is encoded in their own FairPlay DRM.
Apparently the irony that Somers is suing one monopoly because it doesn't support a competing monopoly's file structure is lost within the transcript of the lawsuit.
Details of the court filing can be found here.