In this paper, a case study investigating the experiences from evolution and modification of reusable assets in product-line architectures is presented involving two Swedish companies, Axis Communications AB and Securitas Larm AB. Key persons in these organisations have been interviewed and information has been collected from documents and other sources. The study identified problems related to multiple versions of reusable assets, dependencies between assets and the use of assets in new contexts, The problem causes have been identified and analysed, including the early intertwining of functionality, the organizational model, the time to market pressure, the lack of economic models and the lack of encapsulation boundaries and required interfaces.