Problem with NAT and cisco

Hi all,
we have really interesting situation here, maybe someone can help.
we have mikrotik as lastmile AP.
some clients are conected with private adress, they’re just passed through.
some are connected on old private adress (mikrotik was get by acquisition of smaller isp), they’re snated on public IP.
and now the situation.
in peering center is cisco 7600, with firewall card WS-SVC-FWM-1. when people are nated on that card, everything is ok.
when people are passing trough(nated on mikrotik), that firewall card is randomly broking connections.
Cisco says it’s problem on mikrotik snat, but i don’t think so.
I can provide more information if anybody want’s.
Maybe Janus can contact me directly on vilem.kebrt@gmail.com ?
Thanks a lot people.
With regards Vilem

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