PL/Tcl: internal error - cannot create 'normal' interpreter

Hi everybody,

I'm stuck getting PL/Tcl to work with postgresql-7.3.2 and Tcl8.4 under OS X
10.2.4. I compiled from source with the following configure flags:

./configure --with-includes=/sw/include/ --with-libraries=/sw/lib --with-tcl
--with-tkconfig=/Library/Frameworks/Tk.framework

The pgtclsh seems to work fine but calling a function in a database from
psql results in the following:

> ERROR: pltcl: internal error - cannot create 'normal' interpreter

I ran the test suite, which also produces the above error. A search of the
archives didn't return much, so I'm pretty clueless now.

Any ideas as to what might be the problem or how to get some more detailed
info greatly appreciated...

cheers

Fabian