Oracle ORA-01805 on Oracle 11g database

I determined that I had version 11_2_0_1 of the instant client installed. Upgrading to 11_2_0_2 seems to have relieved this issue. However, I'm still not clear on how the instant client manages it timezone file, or even where it is or what it is. All the sources I've read say to ensure that the client and server have the same timezone file version, but it's not clear to me how that is actually done on the client. Perhaps it's not something I can directly maintain beyond using a different version of the instant client?

Use "genezi -v" to know the timezone file version.

Here is a sample in my Linux box:

$ genezi -v
Client Shared Library 32-bit - 11.2.0.2.0

System name:    Linux
Release:    2.6.32-34-generic
Version:    #77-Ubuntu SMP Tue Sep 13 19:39:17 UTC 2011
Machine:    x86_64

Operating in Instant Client mode.
Small timezone file = timezone_14.dat
Large timezone file = timezlrg_14.dat