It sounds like
HKEY_CLASSES_ROOT\MIME\Database\Content Type\audio/mpeg
or
HKEY_CLASSES_ROOT\MIME\Database\Content Type\audio/mpg
value "Extension" is set to ".mp2". Is it?

--
Speaking for myself only.
See http://zachd.com/pss/pss.html for some helpful WMP info.
This posting is provided "AS IS" with no warranties, and confers no rights.
--
"nick" <nick@discussions.microsoft.com> wrote in message
news:0C28C0B2-2F40-4478-BA4D-B9157D472452@microsoft.com...
> Hi Andre..
>
> Thanks for the reply.
>
> It makes no difference if I show/hide the extensions for known file types.
>
> I think this is a specific file association issue but i'm unable to find
> the
> registry key which needs editing. Have looked at .mp2, QuickTime.mp2,
> RealPlayer.MP2.6, WMP11.AssocFile.MPEG but everything looks ok.
>
> Thank you for the response though
>
> "Andre Da Costa[ActiveWin]" wrote:
>
>> Try hiding the File Extension for .MP2
>>
>> Show or hide file name extensions:
>> http://windowshelp.microsoft.com/Win...389da1033.mspx
>> --
>> Andre
>> Blog: http://adacosta.spaces.live.com
>> My Vista Quickstart Guide:
>> http://adacosta.spaces.live.com/blog...3DB!9709.entry
>> "nick" <nick@discussions.microsoft.com> wrote in message
>> news:8DFDBC1E-BF0C-43E4-81BE-369A8B70C5FC@microsoft.com...
>> > Hi..
>> >
>> > I have been trying to fix an annoying problem in IE7 and i'm pretty
>> > much
>> > out
>> > of ideas so would appreciate some advice or suggestions please.
>> >
>> > Everytime I download any MP3 files from any website, IE7 sees the file
>> > as
>> > an
>> > MP2 file so I then have the inconvenience of having to select Save ->
>> > change
>> > the 'Save as type' option to 'All files' then add .mp3 to the end of
>> > the
>> > file
>> > which is a bit of a pain.
>> >
>> > I have tried unregistering and disabling QuickTime and RealPlayer
>> > addons
>> > but
>> > no effect then I tried disabling all addons just incase there was a
>> > confliction somewhere but the same thing happens.
>> >
>> > I run a dual boot system (XP/Vista) with pretty much the same software
>> > on
>> > each installation but the problem only exists in IE on the Vista
>> > installation.
>> >
>> > I'm kinda out of ideas so would appreciate some help please.
>> >
>> > Thanks..
>> >
>> > Nick
>> >
>>
>>
>>