rare download problem.

[compaddict]

hello guys. :)
i've just reformatted my pc and now i was able to get it back in tip-top shape [including my apps].

but then when i browse youtube.com, i find that it cannot load the video files.
i know it can load flash files because it can load the player itself. therefore i thought the problem might be with the embedded files.

it wasn't.
i found out that when i download a certain file, it is first "loaded", then the "open/save" dialog box appears. when i click that, i see that the file has already been downloaded.
i don't like it because i don't have a clue whether it's downloading or it's stuck.

for example, i download a 10MB file. i first wait for several moments...
...
...
then the open/save/cancel dialog box pops up [i use firefox]
if i click save, the file finishes download IMMEDIATELY.

i thought the problem might be with firefox.
it wasn't: the same thing happens in Internet Explorer..

please help me.. :)
this is bothering me for two weeks now.
thanks for any help. God bless!

:D