Automatic Rebuild of Intersection Curves

Hi, I'm working with an assembly in Solidworks 2007. The assemblycontains multiple solid-body parts and an intersection curvebetween the parts. The intersection curve is created by selectingeach solid-body part from the appropriate solid body folder in thedesign tree. In the Animator, one of the parts moves and the otheris stationary and the intersection curve is connected to boththroughout the range of motion. My goal is to create a video in AVIformat that shows the movement of the intersection curve as theinterface between the parts changes. The strange problem thatarises is that I can reach this goal in about 10% of my assemblies.In each case I do every step identically (or as close as humanlypossibly). In the instances that succeed, if I simply drag thetime-bar and release it, the intersection curve will update/rebuildautomatically after a second or two. When the process does notwork, the intersection curve will only update after I click therebuild button. To the best of my knowledge, the settings for eachmodel are the same. I've searched extensively through the optionsmenu for any discernable differences and have come up empty. I'massuming/hoping that there's a reason this is happening or thatthere's a solution for this problem. If you have any questions,please don't hesitate to ask.  Any help would be greatlyappreciated. Thank you very much for your time. Rich p.s. I triedto attach two videos in AVI format but got an error message statingthat that format is not permitted. I'll upload the videos todemonstrate my problem if someone can tell me how. Thanks.