We upgraded to 5.2.7 last week and discovered what appears to be a new bug. Columns containing Custom Field data do not display after being added via Configure Columns.
Steps to reproduce:
1) display a list of issues in Issue Navigator
2) use Configure Columns; add a column representing a custom field
3) return to the Issue Navigator and note that the column you added is not displayed.
I made other changes, such as moving and deleting standard columns, and that works fine. The problem appears to be related only to custom fields.