Let's visit standard membership and payment

I have created a new membership level and some want to purchase it and start using it immediately; they already have a paid membership level.  The way I understand it is that the member's current level will run and expire first before the new membership level is applied.  How is this stored?  I know sys_acl_levels_members track the membership level of a member, when it started and when it expires; where is the pending membership level stored?  I want to be able to set the member's current membership level and end the pending membership level they purchased.  What is the procedure I should follow?

While waiting for some feedback on this; I noticed a pending order today.  Most of the time my automatic payments work.  However, today I found a pending purchase; I noticed that the Order ID was blank; perhaps that is part of the problem

Now memberships are queued, so if user has one paid membership and buys another one paid membership, then the new paid membership will start as soon as current paid membership expires. 

You can try to change the following line in modules/boonex/membership/classes/BxMbpModule.php file (near ~160 line):

            $bResult &= buyMembership($iClientId, $iItemId, $sOrderId, true);

to force start new membership immediately.