Block Styles disappear when I applied path restrictions to an unauthenticated user.

Not familiar with skinr. Is this a pathaccess problem or a theme / template problem for skinr?

It's happening to me too over 3 sites. Stylesheet is somewhat corrupted when an anonymous user tries to access denied pages.
This is an example (I've hacked the module to return 404 instead of 403):
http://toxic.cubicarea.it/node --> Corrupted Stylesheet
http://toxic.cubicarea.it --> Normal Stylesheet

Another example: (look to the red block on the right side)
http://www.flordetangoargentino.net/node --> Corrupted Stylesheet
http://www.flordetangoargentino.net/ --> Normal Stylesheet

What's the problem?

getting the same issue. it doesn't render the admin menu properly, as well.

I can confirm this happening on a site using skinr and a Fusion-based subtheme. Aside from blocks styling, my views-slideshow content also get corrupted (all items displayed at once) which breaks the site layout.

I am also using skinr/fusion.

I had the same issue, without skinr/fusion, but with views_slideshow:

I am not sure that the -patch- works. I am new to using diff to make patches, usually I just read patches and write them in by hand. However, I am pretty sure that using return; rather than exit; to get out of path_access_init has resolved my issues.

+++ ./path_access.module        2011-02-25 02:06:41.000000000 +0000
@@ -67,3 +65,3 @@
     drupal_access_denied();
-    return;
+    exit;
   }

Ugg, scratch that. Post-patch its printing the page twice.
What I have decided to do is use drupal_goto to redirect rather than calling drupal_access_denied.
If I decide I care Ill tell it to log the event as well. Sorry my resolution isn't of perfect assistance to the rest of you.

The double page effect happens else where in Drupal for a few major revisions of Core now. I just can't remember the place i've seen it within Drupal now! :-(

I suspect this is because this module is is calling exit(); in hook_init, mening that other modules will not get a chance to finish their initialization.