Adobe Plugin staling my net connection?

At the end of June I got an update alert for my adobe flash on firefox and installed it. Right away the sites I would go to with streaming video (youtube, gametrailers, G4) would load slowly. Sometimes all the video windows went gray and had this Plugin malfunction message in it. (forget exactly what it said). Web surfing got much slower too.


I found this "plugin-container.exe" in the task list which was talking up allot of resources so I assumed that was new and googled it...I found a help thread that told someone to:


"type About:config in the address bar, filter for dom.ipc.plugins.enabled.npswf32.dll and change that to false. Flash will run in the program proper."


After doing that the Plugin container was gone in the task menu but... allot of the symptoms didn't go away. No more plugin crashes but web pages where loading so sluggishly and videos loading so much slower. Then my gmail started telling me there was something wrong with my net connection. Finally the connection started going even slower...recently pages half load or just time out.


The timing of it all suggests that either the plugin or the thing it did to try and fix it is somehow the problem. But I don't know how my plugin manager could effect my connection performance so I wonder if it's something else?


Sorry for quoting another forum but because I got bad advice on a forum I don't trust I thought I'd ask here 'cause this is where I always get things fixed.


Windows XP SP3
Pentium Dual-Core CPU E5200 @ 2.50GHz
2 GB ram
Realtek RTL8139/810x Ehternet NIC
Avast
D-link wired router
DSL connection


Just bought the PC in February and it's been running like a dream until this. So there's little build up of other software.