Values of ReadOnly fields are deleted during update action.

I have upgraded JIRA from version 4.1.1 to latest one and I have noticed that during "Edit" action all values from ReadOnly custom fields vanish.
I have fixed it by adding "edit" resource to the all custom read only fields:
for example
In system-customfieldtypes-plugin.xml file I have added the following line to the "importid" customfield section

<resource name="edit" type="velocity" location="templates/plugins/fields/edit/edit-readonly-basictext.vm"/>

and I've added new file based on existing edit-basictext.vm

#customControlHeader ($action $customField.id $customField.name $fieldLayoutItem.required $displayParameters $auiparams)
    <input class="text" id="$customField.id" name="$customField.id" type="text" value="$textutils.htmlEncode($!value)" readonly="readonly" />
#customControlFooter ($action $customField.id $fieldLayoutItem.fieldDescription $displayParameters $auiparams)

I have fixed it one day after upgrade so I had to recover only few issues but this very serious bug. I don't know whether it concerns only version 5.0.6 or maybe other previous versions.