Database running as wrong user on AIX 6.1

I've hit a strange problem on AIX 6.1 while installing 11.2.0.2.0 single instance database. Role separation is being used i.e. grid infrastructure owner is grid and RDBMS software owner is oracle.Both users have different UIDs:

uid=10413(oracle) gid=10006(dba)

uid=11145(grid) gid=10006(dba) groups=10019(asmadmin)

Whenever I create the databases the processes are owned by the grid user. I've re-installed it three times using OUI and DBCA with the same result.

[lnelson1@hostname lnelson1]$ ps -ef|grep pmon |grep -v grep

    grid 11010150        1   0   Jan 21      -  1:56 asm_pmon_+ASM 

    grid 14680242        1   0 23:00:21      -  0:12 ora_pmon_tibhl7 

Has anyone else encountered this issue before?

Thanks,