# Collision detection in external class off by one frame

**URL:** <https://forum.kirupa.com/t/collision-detection-in-external-class-off-by-one-frame/280398>\
**Category:** flash\
**Created:** [January 27, 2009, 6:24am UTC](https://forum.kirupa.com/t/collision-detection-in-external-class-off-by-one-frame/280398 "2009-01-27T06:24:18Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![dandylion13](https://avatars.discourse-cdn.com/v4/letter/d/c89c15/32.png) [@dandylion13](https://forum.kirupa.com/u/dandylion13)\
**Post date:** [January 27, 2009, 6:24am UTC](https://forum.kirupa.com/t/collision-detection-in-external-class-off-by-one-frame/280398/1 "2009-01-27T06:24:18Z")

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Hello,

I’m doing collision testing between 2 objects. When I run the collision code in the Document Class, or inside any of the classes of the display objects, it’s perfect. If I move the code to an external class which is not on the display list, it works, but the collision precision seems off by about one frame.

Does anyone know whether classes that aren’t on the display list process ENTER\_FRAME events differently or at lower priority than classes that are on the list? I’ve found no information on this and wonder whether anyone has experienced something similar.

Thanks!