You're right - it was the router. I tried connecting the laptop
directly to the modem and browsed the internet - it worked perfectly.
The problem must be with the Wifi router, right? Though I have no idea
how a router could be causing such weird errors! And why only on
Vista!
While it's possible to tweak MTU setting in Vista (cf.
http://www.broadbandreports.com/forum/r19900056-Tweak-Test-Vista-MTU), it's
generally not advisable (cf. disclaimer at
http://www.broadbandreports.com/tweaks).
White Paper: MTU in Vista
http://download.microsoft.com/download/c/2/6/c26893a6-46c7-4b5c-b287-83021659734
0/TCPIP_Reg.doc
Before going this route, make sure the router has the latest firmware update
and check to see if it's Vista-compatible. You may benefit from a newer
router.
Consider posting further about this in
microsoft.public.windows.vista.networking_sharing and/or
microsoft.public.windows.vista.performance_maintenance newsgroups.
Click on either of the following links to open the newsgroup in your default
NNTP newsreader:
news://msnews.microsoft.com/microsoft.public.windows.vista.networking_sharing
news://msnews.microsoft.com/microsoft.public.windows.vista.performance_maintenance

Signature
~Robear Dyer (PA Bear)
MS MVP-IE, Mail, Security, Windows Desktop Experience - since 2002
AumHa VSOP & Admin http://aumha.net
DTS-L http://dts-l.net/
> You're right - it was the router. I tried connecting the laptop
> directly to the modem and browsed the internet - it worked perfectly.
> The problem must be with the Wifi router, right? Though I have no idea
> how a router could be causing such weird errors! And why only on
> Vista!
<paste>
PA Bear [MS MVP] wrote:
> Does the behavior persist if you connect directly to the router? ...the
> modem?
[quoted text clipped - 24 lines]
>>
>> Can you help me please? This is driving me crazy!!