The textcart extension uses the "&$_SESSION" term in quite a few places - do they all have to be changed?
Line 412 in modules/textcart/purchasing/po_entry_items.php (also present in corresponding core file modules/purchasing/po_entry_items.php):
$cart = &$_SESSION['PO'];
Line 87 in modules/textcart/inventory/adjustments.php
$adj = &$_SESSION['adj_items'];
Line 83 in modules/textcart/inventory/transfers.php
$tr = &$_SESSION['transfer_items'];
In modules/textcart/sales/sales_order_entry.php
Line 295:
$cart = &$_SESSION['Items'];
Line 244:
$cart = &$_SESSION['Items'];