As in the title, the corners - normally supposed to be transparent - stay pink (R:255 G:0 B:255). That happens only with the included themes. The Windows7 Example theme from the Beta (4) Topic does not have this issue. Both background images use the same color for transparency (Full Magenta) but the default one appears to use png transparency (for chrome?).
Do they use the same theming engine? The custom theme seems not to be affectable by chrome options, so maybe that is the cause.
My enviroment: XP 32 SP3 Admin, classic theme, Platform 2.0 Beta 5.
I have not found that as a bug and just file it because John asked for it in the theme preview (adressed to another user, but I think I could act as deputy poster).
That should actually be known as it is listed as known issue for the Leo release (2.0B5).
If that bug is adressed in the upcoming Release Candidate it can be marked as closed immediately.