I've seen this bug in Adobe's JIRA so nothing much you can do for now DateTimeAxis is quite bugged.
By the way, is it me or mx:datavisu is on low priority these days ? Maybe the team is working on a spark version ?
Want to ask one thing are u using Eclipse for building this application ?
Simply inplace of s and fx name space use only mx name space. and this will solve your problem.
I tried ur code in flex builderSDK and over there it is working fine. So once working with this do let me know??
I am using flex sdk 4.00(build 10485) in flash builder . Can you please provide me solution for this SDK .
Shoot! Having the same issue here. At least, I am glad to find out it's a bug.