Trouble upgrading cacti

Hi!

I was using the version 0.8.7i of cacti, I decided to upgrade it to 
version 0.8.8a because I was concerned it has the PIA installed by default.

I followed this page to do it: 
http://www.cacti.net/downloads/docs/html/upgrade.html

After doing it, I cannot see any graph! All of them appear as a broken 
images. When I upgraded, I had to reset the spine path to 
/usr/sbin/spine, as it appeared blank, but I think the rest of the 
configuration is ok.

In the logs I only could see this in cacti.log:

07/01/2012 01:15:40 AM - UPGRADE: Poller[0] upgrade_to_0_8_8 upgrade 
table poller_item
07/01/2012 01:15:40 AM - UPGRADE: Poller[0] upgrade_to_0_8_8 table 
poller_output: dropping old PRIMARY KEY
07/01/2012 01:15:40 AM - UPGRADE: Poller[0] upgrade_to_0_8_8 upgrade 
table poller_output
07/01/2012 01:15:40 AM - UPGRADE: Poller[0] upgrade_to_0_8_8 upgrade 
table user_log
07/01/2012 01:15:40 AM - UPGRADE: Poller[0] upgrade_to_0_8_8 install 
table plugin_config
07/01/2012 01:15:40 AM - UPGRADE: Poller[0] upgrade_to_0_8_8 install 
table plugin_db_changes
07/01/2012 01:15:40 AM - UPGRADE: Poller[0] upgrade_to_0_8_8 install 
table plugin_hooks
07/01/2012 01:15:40 AM - UPGRADE: Poller[0] upgrade_to_0_8_8 install 
table plugin_realms
07/01/2012 01:15:40 AM - UPGRADE: Poller[0] upgrade_to_0_8_8 upgrade 
table data_template_data
07/01/2012 01:16:10 AM - AUTH LOGIN: User 'admin' Authenticated
07/01/2012 01:20:01 AM - POLLER: Poller[0] WARNING: Cron is out of sync 
with the Poller Interval!  The Poller Interval is '300' seconds, with a 
maximum of a '300' second Cron, but 599 seconds have passed since the 
last poll!
07/01/2012 01:20:02 AM - SYSTEM STATS: Time:0.6519 Method:spine 
Processes:1 Threads:1 Hosts:3 HostsPerProcess:3 DataSources:40 
RRDsProcessed:27
07/01/2012 01:25:02 AM - SYSTEM STATS: Time:0.5627 Method:spine 
Processes:1 Threads:1 Hosts:3 HostsPerProcess:3 DataSources:40 
RRDsProcessed:27
07/01/2012 01:30:01 AM - SYSTEM STATS: Time:0.5376 Method:spine 
Processes:1 Threads:1 Hosts:3 HostsPerProcess:3 DataSources:40 
RRDsProcessed:27
07/01/2012 01:35:02 AM - SYSTEM STATS: Time:0.5998 Method:spine 
Processes:1 Threads:1 Hosts:3 HostsPerProcess:3 DataSources:40 
RRDsProcessed:27

And so on, so I understand there are not further errors after upgrading. 
But in poller-error.log I see a lot of lines like these:

Cannot adopt OID in NET-SNMP-AGENT-MIB: nsLogLevel ::= { nsLoggingEntry 1 }
Cannot adopt OID in NET-SNMP-EXTEND-MIB: nsExtendResult ::= { 
nsExtendOutput1Entry 4 }
Cannot adopt OID in NET-SNMP-EXTEND-MIB: nsExtendOutNumLines ::= { 
nsExtendOutput1Entry 3 }
Cannot adopt OID in NET-SNMP-EXTEND-MIB: nsExtendOutputFull ::= { 
nsExtendOutput1Entry 2 }
Cannot adopt OID in NET-SNMP-EXTEND-MIB: nsExtendOutput1Line ::= { 
nsExtendOutput1Entry 1 }
Cannot adopt OID in NET-SNMP-EXTEND-MIB: nsExtendOutLine ::= { 
nsExtendOutput2Entry 2 }
Cannot adopt OID in NET-SNMP-EXTEND-MIB: nsExtendLineIndex ::= { 
nsExtendOutput2Entry 1 }
Cannot adopt OID in NET-SNMP-AGENT-MIB: nsNotifyStart ::= { 
netSnmpNotifications 1 }
Cannot adopt OID in NET-SNMP-AGENT-MIB: nsNotifyShutdown ::= { 
netSnmpNotifications 2 }
Cannot adopt OID in NET-SNMP-AGENT-MIB: nsNotifyRestart ::= { 
netSnmpNotifications 3 }
Cannot adopt OID in UCD-SNMP-MIB: laErrMessage ::= { laEntry 101 }
Cannot adopt OID in UCD-SNMP-MIB: laErrorFlag ::= { laEntry 100 }
Cannot adopt OID in UCD-SNMP-MIB: laLoadFloat ::= { laEntry 6 }
Cannot adopt OID in UCD-SNMP-MIB: laLoadInt ::= { laEntry 5 }
Cannot adopt OID in UCD-SNMP-MIB: laConfig ::= { laEntry 4 }
Cannot adopt OID in UCD-SNMP-MIB: laLoad ::= { laEntry 3 }
Cannot adopt OID in UCD-SNMP-MIB: laNames ::= { laEntry 2 }
Cannot adopt OID in UCD-SNMP-MIB: laIndex ::= { laEntry 1 }

So I assume there's the error. Could someone tell me how to solve this? 
I'm trying to look for some info but I see nothing about this...

Thank you very much!

Nicolás

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