date formatting not correct in view

I added a date field formatted with a custom format m_Y, that has an extra space and underscore added.

I have set a rewrite on the date output as *[field_date]* to show exactly what is the content that is formatted by my format month-key (m_Y ie 04_2012). I can use 'trim to length' to resolve this now but I rather have my formats untouched ;-)

When I use this formatted field as replacement pattern in another field (why is selected field order important to have selected fields available as replacement pattern for a field on position x ?), it has the same output (for instance 'list-page/04_2012 _'), so the formatting seems to be consistently wrong ... in my case.