[bug] Server problems & manga requests thread problem

[Drahken]

For the past couple days now, any time I try to view the manga requests thread, the site hangs, then winds up force-logging me off the main site (not the forum). I don't know if the thread is directly tied to the problem or if the timing is coincidental.
As far as the thread itself, I have not been able to view it at all during this time. Every time I try (regardless whether I click the thread title, the "last page" link, or anything else) I just get the following fatal error:

( ! ) Fatal error: Allowed memory size of 268435456 bytes exhausted (tried to allocate 1422441185 bytes) in /home/anime/public_html/forum/vbseo/includes/functions_vbseo_ui.php(237) : eval()'d code on line 237
Call Stack
# Time Memory Function Location
1 0.0356 5677256 {main}( ) ../vbseo.php:0
2 0.0716 11562952 require( '/home/anime/public_html/forum/showthread.php' ) ../vbseo.php:1397
3 2.4984 25361856 vB_Postbit->construct_postbit( ) ../showthread.php:1100
4 2.4993 25377248 eval( ''if(defined(\'VBSEO_ENABLED\') && VBSEO_ENABLED)\r\n{\r\n@vbseo_complete_sec(\'postb it_display_complete\', $post);\r\n$post[\'message\'] = vbseo_prepare_int_replace($post[\'message\']);\r\n$post[\'message\'] = vbseo_process_content_area($post[\'message\']);\r\n\r\nif(class_exists(vBSEO_UI))\r\n{\r\nvBSEO _UI::postbit_hook($post, $template_hook);\r\n}\r\n\r\n}\r\n'' ) ../class_postbit.php:294
5 2.4996 25397872 vBSEO_UI::postbit_hook( ) ../class_postbit.php(294) : eval()'d code:9
6 2.4996 25403736 vBSEO_UI::likeshare_bit( ) ../functions_vbseo_ui.php:86

edit:
I did some experimenting, and the source of the problem seems to be something with the "posts per page" option. I have mine set to 20. I just went in and tried setting it to 5 and 10, and both worked fine. When I set it back to 20 though, the problem came right back.

What's really odd though is that the manga thread is the only thread which is having this problem. Other long threads (including the anime requests thread, right here in the exact same subforum as the manga one) work fine with the 20 posts per page setting. (...And the manga thread had been working fine with it until sometime yesterday.)

edit 2:
With the error being about VBSEO (ever notice how EVERY forum error is because of VBSEO?), and the fact that the manga requests thread has MU links for each requested series, I wonder if the problem has to do with the clunky VBSEO addon trying to process too many links at once?
....Although that doesn't explain why it started happening so suddenly. I have always had my options set to show 20 posts per page, but I have never had this problem until now.

edit 3:
When I lower my posts per page & look at the thread, I see there is a slew of deleted posts (which unfortunately leave remnants visibles to mods), I suspect that this is the source of the problem. Even with 10 "posts" per page, the forum still shows several dozen deleted posts per page in addition to that.