I have now done further tests with the system. Added /SMP switch to acpi.psd driver and remmed out all mmos2 related lines in config.sys. Following trap screen resulted in late phase of booting (after jfs chkdsk and network related stuff):
Exception in module: OS2KRNL
TRAP 000e ERRCD = 0000 ERACC = **** ERLIM = ******** CPU=01
EAX = fc4c7770 EBX = ffe8b600 ECX = 00e89eb6 EDX = fff0a89d
ESI = f9800034 EDI = f970f6b0 EBP = 00004e28 FLG = 00010287
CS:EIP = 0168:fff37212 CSACC = c09b CSLIM = ffffffff
SS:ESP = 1530:00004e04 SSACC = 1097 SSLIM = 00003fff
DS = 0160 DSACC = c0f3 DSLIM = ffffffff CR0=8001001b
ES = 0160 ESACC = c0f3 ESLIM = ffffffff CR2=fc4c7770
FS = 0000 FSACC = **** FSLIM = ********
GS = 0000 GSACC = **** GSLIM = ********
The system detected an internal processing error at location
##0168:fff0f667 - 000f:e667.
Internal revision 14.103a_SMP
The system is stopped. Record all of the above information and contact
your service representative.
It seems that SMP switch is causing the trap. Version 3.02 did not do this. Some values in trap screen change if different lines are remmed out in config.sys.