Group should scroll vertically but is expanding to infinite in width

I have a group for which I want to enable horizontal scrolling. Vertically the group should be as wide as possible (100%).

<s:Scroller left="0" right="0" top="0" bottom="0"
        visible="{isVisible}"
        horizontalScrollPolicy="off"
        includeIn="stateA">
    <comps:MyComp 
            horizontalScrollPosition="0" verticalScrollPosition="0"/>
</s:Scroller>

Now in MyComp are two other components having also a width of 100%.

Now if I start the application the MyComp-component is about 200px wide开发者_运维技巧 and starts to expand its width to infinity. This is like some transition or animation and I don't know how to stop it. Setting something like maxWidth would solve the issue, but I don't want to set explicit values.

Any ideas what's wrong?

problem was, that the MyComp component (which is actually a Group) got a width of 100% defined. After removing this value, all works like expected.