If you intend Access to perform a numeric comparison, lose the quotes, i.e.:
If Text430.Value <= 55 Then
With the quotes, it will most likely perform a string comparison, i.e.
character by character. As a result, "11" is less than "2" (because the
first character - 1 - is less than the first character of the other string -
2.)
If Text430 is bound to a Text type field, Access may still perform a string
comparison. If it is unbound, set its Format property to General Number so
Access knows you want the value treated as a number (and it won't let you
enter non-numeric values.)
For a solution without code, replace right-click lbl6 and Change To | Text
box. Then set its Control Source to:
=IIf([Text430] < 55, "Some text", Null)