All of your icons that you plan to use for OD should be kept in your OD image folder in My documents....this makes sure that OD can find them & prevents other programs from * hijacking them ...this hijacking would only occur with ico images..the format Windows uses.
And .PNG icons are best used with OD...higher quality image & haven't heard of them being hijacked.
After having gone through the process of setting up your docks ....Save the Theme
Open Configuration panel...on the left select ..Themes.. then see...Save Theme As...select & choose the name... It's My Secret