For the youtube problem thing, look here..
http://forum.kaspersky.com/index.php?showtopic=133782


I have the same problem. Youtube or any streaming media would load just fine at first. But after a while it would only play once it has finished downloading the vid itself(it never buffers, but you can monitor your bandwidth, and it will be shown to be downloading the vid like normal). And if that happens, every downloading thing stop working properly. If downloading with browser, smaller file seems fine. Once you click the download this(example) link, nothing comes out. But after a while it will ask for where to save the file. After you choose the location, it will instantly popup saying it has finished downloading. I believe the file was being downloaded in the background as no download progress was shown at all. no popup, no nothing. If download through a download manager, it will never download. For example, IDM will show it's attempting to connect, but it never get past 'Send Get..', but in the bandwidth monitor(not IDM's), it will show something is downloading something. After a while it will time out itself. Usually I have to restart the PC to fix the issue. From my experience it usually happens after I open up 3-5 tab/window at the same time. Things worked just fine and dandy before that.

That workaround up there seems to work for me so far.. those that have the same problem might want to check that out. If you're not confident about it, uninstall KIS2010 and install the 2009 version.

I thought it was my router's problem at first. Because it happens on two different machine on the same network. I even went and replaced it just last night. To my surprise, it still happens. But I need to change the router anyway, so sort of not so much hurt there, but I could still use the old router for a few more months until it finally kong itself or something and buy a new HDD which I really need right now.

Seems OK right now with that workaround. Hope it stays like that. I have lots of stuff in queue in IDM. Usually I left it on most of the time I'm downloading, but after my dad use the pc, I will find the download totally stops.. it still downloads in the background, but nothing gets done.. which is a waste of bandwidth and time! Hope they fix it for real.. can't believe it's been there all this while and they haven't manage to fix it. I find it quite serious since people have to disable the thing for things to work again, or rebooting the PC which is a hassle.. can't expect us to reboot the PC each time that happens.