The Update Installer uses logical procedures when it uninstalls maintenance. The uninstall command works similar to the stack logic in computer science.
Uninstall fix packs in the reverse order that they were installed. The last fix pack installed should be the first one uninstalled.
For example, if maintenance packages A,B,C,D have been installed in that sequence, then the packages should be uninstalled in reverse order: D, C, B, A. This is true if these applications are made up of fix packs, interim fixes or feature packs.