Version: 1.1-CVS (using KDE Devel) Installed from: Compiled sources This sounds a lot like Bug 80303 (with the same error message), but it only happens if a URL is given as argument to amaroK when amaroK is already running. If amaroK isn't yet running when it's started with such an argument there's no problem. The expected behaviour of course is that amaroK opens the given URL and starts playing it. I'm using today's CVS.
This is actually a bug in KDELIBS, namely KCmdLineArgs. It prevents reinitialisation of the class, when KDELIBS is compiled with debug. I'm marking this as a duplicate; please take a look at the bug I'm referring to. *** This bug has been marked as a duplicate of 86776 ***
Please vote for BR 86776, to get this fixed quickly!