Products disappear from a cart occasionally

[Al37]

Joomla 2.5.25
Virtuemart 2.6.10
MySQLi 5.5.27
PHP 5.3.16
nginx 1.0.15
Linux
utf8_general_ci
interface fpm-fcgi



When a user puts a product to the cart it appears there, but when the page is reloaded it occasionally disappears. When the next product is added, the previous item in the cart also can disappear.

Most often it happens with the last added to the cart item.
We tried to keep the cart not in a session but in a special table. When a user calls a cart, we get data from the table. And when a user saves the cart, we store the data in this table.
But this has not solved the problem. Maybe the error has begun to appear less often, but still it happens.
This bug has appeared after the Virtuemart upgrade from version 2.0.20b to version 2.6.4. The update to version 2.6.10 hasn't solved the problem either.
The website uses a plugin Stockable which keeps balances of child products. But products without child products also disappear occasionally.
Could you suggest a possible reason of this bug please?

[69thelememt]

did you ever resolve this?? I have the same issue

[GJC Web Design]

your asking in another thread for this problem in VM1.1 - this is a VM2 thread and totally unrelated -