Weird BASIC bug in Zap

I was contacted earlier with somebody noting that ZapBASIC gets a ‘*’ wrong when it was used as a multiplier, turning the rest of the line green (and gibberish) which means it is mistakenly interpreting it as a *Command.

He supplied a full program, but this is enough to show it:

IF VAL(FNbytes)*1024>1024*y% THEN col%=9 ELSE col%=11

These work (FNbytes returns a number as a string):

IF VAL(FNbytes(0))*1024>1024*y% THEN col%=9 ELSE col%=11

IF VAL( FNbytes )*1024>1024*y% THEN col%=9 ELSE col%=11

IF (VAL(FNbytes))*1024>1024*y% THEN col%=9 ELSE col%=11

But the line as given does not.
Does anybody have any familiarity with the internals of ZapBASIC?

Oh, thank goodness.

Just rummaged, dug up my EeePC and started up the emulator.
Zap v1.40 from 24th October 1998 does the exact same thing. So it looks like this bug has always been present.