User can only purchase nodes once

Pay Per Node only appears to work the first time that a user purchases the node, but if I want to post a second node of the _same_ type, it won't let me buy it. I _can_ make 1 purchase of another type of node, but can't seem to re-purchase any

I've tested this several times. I (1) create a new user (2) Log in as the new user (3) Purchase a node for "position available" (4) Post the Node by going to node/add/position_available (5) Purchase another node of the same type (6) When I got to the node/add/position_available address to enter in the 2nd node purchased, I just get the screen of available content to add that one gets normally by going to node/add. The position available isn't listed there. Any ideas what might be causing this? I thought it might be a chaching or session issue, but dumping the cache and clearing my session cookies didn't solve it.

The second time that I try to buy, it lets me get all the way through the purchase process and charges me, but never adds the node I paid for.

If I set the # of nodes the user is allowed to buy to 100, they are allowed to create 100 and I can create multiple entries, but if I return to buy another 100, they aren't added.

Thanks for your help,

Greg