it happens when.. the dimensions are very low. i mean around (1 - 25mm) it oftern happens in CATIA. but thats not the real error.. still you can use features
May be my idea will help you.
You can use the below setting in the Catia V5 to get the geometry. Just go to Tools --> Options --> Display --> Performance Tab and change the 3D Accuracy to the lowest value, (i.e). 0.01. as shown in the below Picture