Costumer session and checkout error

[miaudogs]

Hi,

 

When my clients make the login the page becames too slow. Sometimes the client takes 30min. to complete the buy, and sometimes can't conclude the buy at all.

Without the login session the page functions are all OK. The problem only beggins when we add articles to the shopping cart or make login.

Can someone tell me what can I do to solve this problem, please?

I'm not a programmer so I really don't know what's happening or what to do.

 

Thanks