Fatal errors when administrating

I get errors such as:
Fatal error: Allowed memory size of 8388608 bytes exhausted (tried to allocate 292094 bytes) in /var/www/html/includes/class_core.php on line 395
and
Fatal error: Allowed memory size of 8388608 bytes exhausted (tried to allocate 44 bytes) in /var/www/html/includes/adminfunctions.php on line 2825
when trying to delete threads.

And in at least one of my forums (I've only tried two), small business, I see a blank page after submitting a new thread. But in another forum it appears to work correctly.

Hello!

Hm.. which version do you use - zend or ioncube? Can you provide me a test account details in PM to check the issue at your forums?

Thank you!

I'm using ioncube.

Other errors also occur for regular members, such as listed in a PM that one of my admins sent me:

1. I click on a question under "New Posts" and I get a blank (totally blank) screen, but the address bar shows address:
http://www.askmehelpdesk.com/marriag...or-advice.html

2. When I AM able to get to a thread (using Advanced Search for threads with 0 replies) and I use the "Answer this Question" button, I also get redirected to a blank page (but when I go back into it, I see my response did get posted.

3. When using the quick reply window, the screen locks up after hitting "Submit" but appears to be "working". Another click of the Submit button, of course, results in the post getting posted twice.

4. When deleting a post, I'm redirected to an error page:

Fatal error: Allowed memory size of 8388608 bytes exhausted (tried to allocate 128 bytes) in /var/www/html/includes/adminfunctions.php on line 2825

...but when I go back to the thread, I do see that the post was successfully deleted.

PM sent

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