Difference Between $Data->Account->Name And $Data->Account["name"]

I have what I hope is a really easy question…

I have two machines (Apache 2.2.27, PHP 5.5.11). Project code is moved between machines using subversion.

Machine A: CGridView with related model works correctly. ‘value’=>’$data->account->name’

Machine B: The above value line throws an error "Trying to get property of non-object".

       If I change it to 'value'=>'$data->account["name"]' it works.

Does anyone have an idea what could account for the difference?

My first thought was PHP versions (I had been on php 5.3 – i.e. no short array syntax, etc), but I have both machines on 5.5.11 now.

Also, does that type of referencing have a "name" that I could search on. Searching on relations and recursive object referencing, etc is just too broad. Better search terms would be welcome!

Thanks much!

Ran some more tests. This code also demonstrates the problem (and elminates the CGridView):

$iterator = new CDataProviderIterator($model->search());

foreach($iterator as $i)

{

print $i->firstname . ' [' . $i->account["address"] . '] '  .  ' (' . $i->account->address . ')' . "<br>";

}

Machine A. Works perfectly. Machine B dies on the second reference to address ($i->account->address).

Any php.ini settings that might be relevant to this?