In legacy admin interface, i tried to create a class with most of all existing datatypes in it.

Text line
Authors
Checkbox
Comments
Country
Date
Date and time
Email
Enum
File
Float
GMap Location
ISBN
Identifier
Image
Ini Setting
Integer
Keywords
Matrix
Media
Multi-option
Object relation
Option
Star Rating
Subtree subscription
Text block
Time
URL
XML block

When i finished to fill informations for each datatypes, i tried to save my new class.
I got a validation error from one of my datatype "INI Settings" (filled with : file "test", section "test", parameter "test", in "override" location and with a integer value type)
This is the error :

The class definition could not be stored.
The following information is either missing or invalid:
attribute 'new attribute17': Ini Setting (323)

Then, when my form was reloaded, some (most?) of the fields were re-initialized within default value and i lost my filled informations :
Fields reinitialized :
Text line
Authors
Checkbox
Comments
Email
Enum
File
Float
GMap Location
Identifier
Image
Integer
Keywords
Matrix
Media
Multi-option
Object relation
Option
Star Rating
Subtree subscription
Text block
URL

Is that normal ?