Problem connecting with DBD::Sybase after upgrading OCS to 12.5.1 ESD#12

Since I upgraded the OCS-libraries to 12.5.1 ESD#12 (EBF13138) I cannot 
connect to any database using DBD::Sybase 1.07.

Running "make" is no problem, but when trying "make test" I always get 
following message:
OpenClient message: LAYER = (5) ORIGIN = (3) SEVERITY = (5) NUMBER = (4)
ct_connect(): network packet layer: internal net library error: There 
was an error encountered while establishing the connection.

I use Solaris 9 (64 bit), ASE 12.5.3 ESD#6 (32 bit), Perl 5.8.5 and DBI 
1.50.

When I do the same testing with OCS libraries 12.5.1 ESD#2 (EBF 11758), 
everything is ok.

Interfaces-file, user, password, environment: all checked and ok.

Has anyone an idea?

I also tested DBI 1.48 and DBD::Sybase 1.05, which showed the same 
behaviour.

Thank you in advance,
Dirk