Can't install the module on PHP 5.2 (White Screen of Death)

So i tried to install the 7.x-2.x-dev and the 7.x-2.0-beta versions and when i try to install via drupals web GUI (/admin/modules), i get redirected to the url:
modules/list/confirm and there is no content, just a white screen (aka the WSoD).
It fails to install.

If I try to enable authcache and authcache_builtin via command line interface (drush) it does at least successfully install...
but the whole site doesn't work then (entire site gets WSoDeath).

Thought maybe it needs the settings.php settings for authcache but those didn't help either...
Does it matter that I have PHP 5.2.17?
Using Drupal 7.26.
Nothing in php error logs (error_reporting is set to E_ALL & ~E_NOTICE | E_STRICT and display_errors is also on).
Nothing in the watchdog logs either.

7.x-1.7 installs fine with no white screen errors.

Anything I can check to see why the 7.x-2.x installs are erroring?

Thanks,
Ari

P.S.
my php.ini settings are these so pretty sure its not the memory limit and think the error happens way before 2400seconds:
max_execution_time = 2400 ; Maximum execution time of each script, in seconds 20m
max_input_time = 60 ; Maximum amount of time each script may spend parsing request data
memory_limit = 1500M