using enterprise library cache application block in COM+

Hi,

I want to cache some stable user information on client side for later use
by VB clients, so I implement enterprise library cache application block in
COM+ serviced component which is developed in C#. I can save and retrieve it
in short time period. The issue is the data will be expired in a few minutes
even if I set the expiration to datatime.maxvalue. Here is code:

cacheManager.Add(key, val, CacheItemPriority.Normal, null, new
AbsoluteTime(DateTime.MaxValue));

Could anyone tell me how to make the cached data alive forever till the
caller remove it?

Thanks.