Netscape 4.75 for Solaris x86 (navigator-v475-us.x86-sun-solaris2.5.1.tar.gz)
make kernel drop into debugger. The kernel compiled from "current" source 
supped at yesterday. On 1.5.1 kernel, 1.5W supped at Jun 5 kernel both 
netscape works without problem, no "unknown svr4 fast trap 2" line appears.


NetBSD 1.5X (BEECH1-NOPCIBIOS) #0: Thu Aug 30 18:49:57 JST 2001
    mochid@dwarf:NetBSD-current/src/sys/arch/i386/compile/BEECH1-NOPCIBIOS
cpu0: AMD K6-2 (586-class), 350.84 MHz
cpu0: I-cache 32 KB 32b/line 2-way, D-cache 32 KB 32b/line 2-way
cpu0: features 8021bf<FPU,VME,DE,PSE,TSC,MSR,MCE,CX8>
cpu0: features 8021bf<PGE,MMX>
total memory = 127 MB
avail memory = 113 MB
using 1658 buffers containing 6632 KB of memory
BIOS32 rev. 0 found at 0xfb2a0



% uname -a
NetBSD gee 1.5X NetBSD 1.5X (BEECH1-NOPCIBIOS) #0: Thu Aug 30 18:49:57 JST 2001     mochid@dwarf:/NetBSD-current/src/sys/arch/i386/compile/BEECH1-NOPCIBIOS i386
% netscape -display xxx:0
unknown svr4 fast trap 2
unknown svr4 fast trap 2
uknknown svr4 faste trap 2
rnel: type 1216652891 trap, code=0
Stopped in pid 295 (netscape) at             0x296:     invalid address
db> t
param.c(867a118,867a018,0,0,ffffffff) at      0x296
Bad user frame pointer: 0x867a090
db> ps
 PID             PPID       PGRP        UID S   FLAGS          COMMAND    WAIT
 298              295        295       7011 3  0x4086         netscape  select
>295              282        295       7011 7  0x4006         netscape
 285                1        285          0 3  0x4086            getty   ttyin
 284                1        284          0 3  0x4086            getty   ttyin
 283                1        283          0 3  0x4086            getty   ttyin
     :
     :
 1                  0          1          0 3  0x4084             init    wait
 0                 -1          0          0 3 0x20204          swapper schedul
db> 

-mochid