Anyone. Anywhere? 
Are you indeed using FPC 2.6.1? I would guess that you're stuck between versions. The conditional code in pascal_parser_intf.pas is defining wst_use_fplist if this is true:
(FPC_VERSION = 2) and (FPC_RELEASE > 6)
With 2.6.1, release should still be 6. Maybe the change of args from TList to TFPList in pasparser.pp (fcl_passrc) has been backported to 2.6.1 or something, thus breaking this code. Add something like this (not tested):
(FPC_VERSION = 2) and (FPC_RELEASE = 6) and (FPC_PATCH > 0)
And report this to WST forum so Innousa can fix it.
Or use FPC 2.6.0 or trunk instead of 2.6.1.
Thanks.
-Phil