I managed to track down where my app was hanging while loading for some
Vista users.  I added showMessage's to the constructor procedures for all
relevant components on the form.

It turned out to be in a 3rd party component which uses the audio Windows
API function mixerGetNumDevs() defined in MMSystem.pas/winmm.dll.  This
function was hanging and not returning.  But this was only the case when the
app was run on a Vista OS in XP Compatibility mode, and only on 4 or 5% of
Vista users.

It appears to be a bug in Vista when in XP compatibility mode, but only with
some soundcard drivers.

There is basically no way to get around it except to not call this function
for Vista or later operating systems when in XL compatibility mode.

Cheers,
Ross.

-----Original Message-----
From: delphi-boun...@elists.org [mailto:delphi-boun...@elists.org] On Behalf
Of sch...@socket.net
Sent: Thursday, 9 July 2009 2:16 p.m.
To: Borland's Delphi Discussion List
Subject: Re: App hanging during load

For what it's worth, I had a similar problem.  After much work trying to 
locate the problem I came to the conclusion that is was in an initialization

section in one of the used components.  I compiled with EurekaLog and had 
the user who was seeing the problem run it.  The bug report the user sent 
back pointed directly to the line of code in a component initialization 
section that was throwing the exception.

I think there's still a 30-day trial of EurekaLog.

Harry

----- Original Message ----- 
From: "Ross Levis" <r...@stationplaylist.com>
To: "'Borland's Delphi Discussion List'" <delphi@elists.org>
Sent: Wednesday, July 08, 2009 5:12 AM
Subject: RE: App hanging during load


>> Do you have any units with initilization sections?
>
> Yes, and that thought had occurred to me some time ago and was tested, but
> all the Initialization sections are executed in the Uses clause in the
> project source before getting to the CreateForm's.
>
> I'm not sure where to go from here.  It doesn't make any sense to me.  It 
> is
> affecting 3 users running Vista and it's a major concern.
>
> Thanks,
> Ross.
>
> -----Original Message-----
> From: delphi-boun...@elists.org [mailto:delphi-boun...@elists.org] On 
> Behalf
> Of zayin
> Sent: Wednesday, 8 July 2009 4:34 p.m.
> To: delphi@elists.org
> Subject: RE: App hanging during load
>
>
>
>
>
>
> On 7/7/2009 10:21:46 PM, Ross Levis (r...@stationplaylist.com) wrote:
>> The user just got around to installing a test version of the app with
>> some
>> ShowMessages in the Form's OnCreate event, but nothing appeared, so it's
>> not
>> even getting to execute the OnCreate event.
>>
>> In summary, the app hangs during
>> Application.CreateForm(TStudioForm, StudioForm);
>>
>> But the OnCreate event for this form is not executed for this user.
>>
>> So what does this mean?  What else is executing during for CreateForm
>> procedure that could cause it to hang?  How can I debug this?  I have
>> MadExcept compiled in but it
>> doesn't activate.
>>
>> Thanks,
>> Ross.
>>
>> > -----Original Message-----
>> > From: delphi-boun...@elists.org [mailto:delphi-boun...@elists.org] On
>> > Behalf
>> > Of Wilfried Mestdagh
>> > Sent: Wednesday, 17 June 2009 10:56 p.m.
>> > To: Borland's
>> Delphi Discussion List
>> > Subject: Re: App hanging during load
>> >
>> > Hello Ross,
>> >
>> > > Application.CreateForm(TStudioForm, StudioForm);
>> > > showmessage('Initialize 3'); <<< IT
>> DOESN'T GET HERE
>> >
>> > You can set some debug information in the OnCreate event of 
>> > TStudioForm.

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