[Serusers] Alias per SIP_DOMAIN? something broken here?

hi, i run an SER which supports multiple realms. all works fine, authentication, calls etc. except one thing: we are in the rare sitiuation of having the same number-block in two different cities. i have aliases for my users (username is areacode +number) which is only the number (without area-code) to support dialing without area-code. but in the case with the two same blocks in different area-codes the alias handling gets a bit confused: # serctl alias show 88999998 <sip:0471288999998@04712.sip.domain.de>;q=1;expires=459311264 <sip:0471188999998@04711.sip.domain.de>;q=1;expires=459311264 so i have two aliases for the same number. any of the numbers is in different SIP_DOMAINS, namely 04712.sip... and 04711.sip..., but even when i state the SIP_DOMAIN to use for the lookup stuff i get: # SIP_DOMAIN=04712.sip.domain.de serctl alias show 88999998 <sip:0471288999998@04712.sip.domain.de>;q=1;expires=459311207 <sip:0471188999998@04711.sip.domain.de>;q=1;expires=459311207 and of course the other way round with 04711. the realm/domain is stored within the alias, so there are two records: 88999998 04711.sip.domain.de sip:0471188999998@04711.sip.domain.de ... 88999998 04712.sip.domain.de sip:0471288999998@04712.sip.domain.de ... with different domains. now, what happens is: when a user from the 04711 area-code calls another user (for him in that same area), he/ she might end up reaching a user with the 04712 area-code. even though the INVITE messages and all state, that the particular (any) user is from the 04711 domain, or 04712 for that matter ... i also tried to name the alias 88999998(a)04712.sip... and so on, but then, it doesn't even find an alias at all. what did i miss? oh, and yes, both realms are defined via an alias-directive in SER.cfg so he treats both as local (or at least it should). any hint would be appreciated. brgds, g. feiner