Attrs invisible/readonly not working correctly in editable tree view

[Karel Marissens]

Steps to reproduce:
1) Install the module in the attachment. The module adds a checkbox to the order lines tree view on a quotation/sales order. When the checkbox is not checked, the field name is made invisible and the field product_uom_qty is made readonly. (Note: this is just an example to demonstrate the problem, not a useful change.)
2) Create a new quotation
3) Add a first orderline and check the new checkbox. Both fields name (description) and product_uom_qty (quantity) are shown on top of each other over the left top of the tree view, instead of in their respective columns. Fill in the field and click somewhere else on the line, the fields now 'jump' to their correct place.
4) Add a second orderline and check the new checkbox. Now both fields appear on top of each other in the description column, on the line above it. (Note: sometimes you have to create a third line to get this behavior)

Note that the behavior can change a bit depending on the browser zoom level. I'm using Chrome v29 on Windows XP.

Used OpenERP version: 7.0-20130812-231022