Simultainius GBAK sessions

I want to start a restore of all my databases at the same. We are moving to 
a new server and I don't want to serialize
GBAK (Gain some time here) .

Interbase 7.5.1.

System Type X86-based PC
Proc: 2 dual core CPU  at 2.66GHZ
Mem: 4GB

I'm starting nine (9) cmd att the same time.
some is going ok and some don't

This is the error:

gbak: ERROR: Unable to complete network request to host "127.0.0.1".
gbak: ERROR:     Error reading data from the connection.
gbak: Exiting before completion due to errors


I have also tried to do a mult backup of all my databases. This also gives 
me some trouble.
messages from some of the cmd:
gbak: writing table constraints
gbak: writing constraint INTEG_1
gbak: writing constraint INTEG_2
gbak: writing constraint INTEG_3
gbak: writing constraint INTEG_4
can't format message 12:169 -- message text not foundwriting constraint 
INTEG_5
gbak: writing constraint INTEG_6
gbak: writing constraint INTEG_7
can't format message 12:169 -- message text not foundwriting constraint 
INTEG_8
gbak: can't format message 12:207 -- message text not found
gbak: writing constraint INTEG_10
can't format message 12:169 -- message text not foundwriting constraint 
INTEG_11
gbak: writing constraint INTEG_12
gbak: writing constraint INTEG_13
gbak: writing constraint INTEG_14
can't format message 12:169 -- message text not foundwriting constraint 
INTEG_15
gbak: writing constraint INTEG_16

These format messages don't apear if I serialize my backups.


I use service_mgr


 Mikael