threadgroup: activeCount and enumerate

[bart zagers]

A question about threadgroup's activeCount and enumerate.
We are looking at the number of threads in our Websphere application server (running on as400). If we look at the number of the recurvisely enumrated threads from the root threadgroup, it is constantly around the same figure of 150 active threads.
However if we look at the activeCount, it rises every day with about 150. It starts at about 170 (which seems normal) and grows over 1000 in a couple of days.
I aware of the "estimated" character of the activeCount number, but it seems odd that it keeps rising and gets so high.
About every week, we have to restart our WAS, can it be related to this issue or don't we have to worry about this and looks elsewhere?

Bart.