vm.memory.size[free] not in the zabbix.history table

[denden]

I'm trying to get some values out of the database for free memory stats for a specific host. I'm getting the item id as follows;

select i.itemid,v.hostid,v.host,i.description,i.lastvalue,i.key_ 
from hosts v, items i 
where v.hostid = i.hostid 
and v.host = 'mymachine' 
and i.key_ = 'vm.memory.size[free]';

Its returning an itemid for me, lets say '1234' for the purpose of this post. When i query the history table as so:

select * from history where itemid = '1234' and clock > '1312260260';

It returns zero rows. However using the same method to retrieve the values for any other itemid works fine (cpu stats ect ect).

Where does zabbix keep its vm.memory.size[free] values? it doesnt seem to be a calculated item and the graphs are rendering for my full 6 month data set, just cant find it in the DB :-/

[denden]

Ignore me, the values are in the history_uint table