Expor/impor access-list signal-range config bug or what?

Sorry, if this is something well known or just my misunderstanding. I got a little problem while reconfigure my router with export/import commands. I’ve configured unsecured virtual ap with an access rule.

The essence of the problem is like that:

[admin@MikroTik] /interface wireless access-list print
Flags: X - disabled 
 0   mac-address=00:00:00:00:00:00 interface=wlan2 signal-range=-90..120 
     authentication=yes forwarding=no ap-tx-limit=1048576 client-tx-limit=0 
     private-algo=none private-key="" private-pre-shared-key="" 
     time=8h-19h,mon,tue,wed,thu,fri management-protection-key="" 

[admin@MikroTik][admin@MikroTik] /interface wireless access-list export compact
# aug/02/2013 14:34:12 by RouterOS 5.25
# software id = PDIL-8ITK
#
/interface wireless access-list
add ap-tx-limit=1048576 forwarding=no interface=wlan2 signal-range=-90 time=\
    8h-19h,mon,tue,wed,thu,fri

As you can see export compact (unlike export without compact param BWT) command leaves only “-90” of value “-90..120”. And so after import it becomes “-90” which doesn’t work - devices cannot connect due to authorization fault.

Looks like one have to correct such an export-compact.rsc manually every time. Am i right? Thanks!