[OS X TeX] Shadows of pdf in Keynote

[Peter Vamos]

I write my presentations in TS and then  cut and paste into Keynote. 
Occasianally, I like to apply shadows to this pdf in Keynote so that

*only the text (and math) characters cast a shadow*.

This used to work but some time ago the behaviour changed: when I 
apply the shadow in Keynote now, the _whole_ pdf will cast a shadow 
as if it were not transparent, it now behaves as just one graphic. I 
don't know what changed: Keynote (I am now using v4.0.1), TS (now on 
v2.14) or Apple's pdf engine (now on OSX 10.5.2 but I think this was 
already the case under late Tiger).This (new) behaviour is unaffected 
even if I change, in TS, the typesetting (TeX and Ghostscript or 
PdfTeX) or the distiller setting.

Any ideas on how I could regain the previous behaviour would be appreciated.