'Security Violation' error upon clicking on thumbnails in Wordpress

Sorry if this is a basic question, but I couldn't find any answers with the search function.

I'm running WPG2 3.0.2, connecting Gallery 2.2 and Wordpress 2.3. Dreamhost is my host.

I'm able to browse albums and insert photos from inside Wordpress, but when I view my posts and click on a thumbnail image I get taken to a Gallery2 'security violation' screen. No further details are provided. There is a link to 'return to the gallery' which also gets me a 'security violation' screen.

Can anyone point me in the right direction as to where to start trying to address this?

I haven't altered any file permissions since my base install...

[edit]

Hmm. Now I can't even see my gallery installation. This time I've got a detailed error message (below). Any ideas? Why would ImageBlock be a problem?

*****************

Security Violation

The action you attempted is not permitted.

Back to the Gallery
Error Detail -
Error (ERROR_BAD_PARAMETER) : Smarty error: unable to read resource: "gallery:modules/imageblock/templates/blocks/ImageBlock.tpl"

* in modules/core/classes/GallerySmarty.class at line 76 (gallerycoreapi::error)
* in lib/smarty/Smarty.class.php at line 1591 (gallerysmarty::trigger_error)
* in lib/smarty/Smarty.class.php at line 1417 (gallerysmarty::_fetch_resource_info)
* in lib/smarty/Smarty.class.php at line 1869 (gallerysmarty::_compile_resource)
* in modules/core/classes/GalleryTemplateAdapter.class at line 806 (gallerysmarty::_smarty_include)
* in g2data/smarty/templates_c/%%2149469851/%%87^87C^87C7F2D4%%sidebar.tpl.php at line 23 (gallerytemplateadapter::block)
* in lib/smarty/Smarty.class.php at line 1871
* in modules/core/classes/GalleryTemplateAdapter.class at line 747 (gallerysmarty::_smarty_include)
* in g2data/smarty/templates_c/%%2149469851/%%56^565^565E1E9F%%album.tpl.php at line 203 (gallerytemplateadapter::theme)
* in lib/smarty/Smarty.class.php at line 1871
* in modules/core/classes/GalleryTemplateAdapter.class at line 747 (gallerysmarty::_smarty_include)
* in g2data/smarty/templates_c/%%2149469851/%%2E^2E1^2E11E2E2%%theme.tpl.php at line 98 (gallerytemplateadapter::theme)
* in lib/smarty/Smarty.class.php at line 1265
* in modules/core/classes/GallerySmarty.class at line 61 (smarty::fetch)
* in modules/core/classes/GalleryTemplate.class at line 186 (gallerysmarty::fetch)
* in main.php at line 479 (gallerytemplate::fetch)
* in main.php at line 94
* in main.php at line 83

System Information
Gallery version 2.2.3
PHP version 4.4.7 cgi
Webserver Apache/2.0.54 (Unix) PHP/4.4.7 mod_ssl/2.0.54 OpenSSL/0.9.7e mod_fastcgi/2.4.2 DAV/2 SVN/1.4.2
Database mysqlt 5.0.24a-standard-log
Toolkits ImageMagick, NetPBM, Gd
Operating system Linux murcielago 2.4.32-grsec+f6b+gr217+nfs+a32+fuse23+tg+++opt+c8+gr2b-v6.194 #1 SMP Tue Jun 6 15:52:09 PDT 2006 i686
Browser Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.9) Gecko/20071025 Firefox/2.0.0.9

Thanks for the reply ozgreg. That sounded like it just might work -- but no dice! I cleared the cookies, and tried a couple other browsers and another computer just to be sure.

Any other ideas? I'm in an awkward position now that I can't use my gallery on its own.