Hook - plugin code - not working after upgrade to vB4.2.3

[Scandal]

I have a report about one of my addons. After upgrade to vBulletin 4.2.3, one or more hooks does not work.
We have:
1. File includes/xml/hooks_myproductid.xml with 1-2 hooks inside (example: myproductid_get_paymentdata)
2. A product with plugin in that hook, with php code.

After upgrade to vbulletin 4.2.3, the plugin's code did not run when its time.

PS: It has to do with a custom placement of a hook code:

PHP Code:

($hook = vBulletinHook::fetch_hook('myproductid_get_paymentdata')) ? eval($hook) : false; 


... inside /payment_gateway.php file.

The strange is that before the upgrade, that hook worked fine.

Any idea?