>>>Is form becoming irresponsive when you start it, or after some user interactions later?
>>
>>I invoke this form several times, it operates just fine, but then it stops. Using Exit button makes it responsive again, then it works for some time, then again after I invoke it it doesn't react and produces a sound of non-reaction when I try to do anything with it.
>
>Most likely, you should activate timer in Form.Activate event and not before it.

I haven't seen your reply yet, but as they say here "Great minds..."

Yes, I'll work in this direction.

But I also need to speak with the user, if she indeed found this problem recently (since I introduced this class just a few days ago) and we're not chasing something else.

UPDATE. Yes, she confirmed she noticed the problem recently.