no message actions for vfs.fs.size

[cirrhus9.com]

Hello:
Zabbix 1.8.10

I have a issue where the {s-db2:vfs.fs.size[c:,free].last(0)}<1G
hasn't sent any actions since August 16, 2013 when the Drive went to 0 bytes free.

Item properties are:
Type: Zabbix Agent
Key: vfs.fs.size[c:,free]
Type of Info: Numeric (unsigned)
Data Type: Decimal
Units: B
Custom Multiplier: 1

Trigger properties are:

{s-db2:vfs.fs.size[c:,free].last(0)}<1G

which I changed this morning from

{s-db2:vfs.fs.size[c:,free].last(0)}<100000

I added Condition (C) this morning hoping to kick-start an email send. It did not.

Action Conditions:
(A) Trigger value = "PROBLEM"
(B) Host group = "AMN"
(C) Trigger = "s-db2:Low free disk space on {HOSTNAME} volume c:"

Action Operations:
Send message:
Single User:
Send only to all:
Email user1 address 1-7,00:00-23:59; NIWAHD
Email user2 address 1-7,00:00-23:59; NIWAHD

It's always worked, so I am at a loss why it's not working now.
Other alerts for this {hostgroup} are working, but I have not gone through any other triggers and there's quite a few hosts with multiple drives.

I appreciate your help.
Thank you,

Update:
After cleaning the \windows\installer directory and reclaiming 2G, I got this:
Low free disk space on s-db2 volume c:: OK
as a Personal note: If it was easy, then I'd be out of J.O.B.

So, I am marking this as SOLVED as I guess the zabbix_agentd had 'no room' to do it's job.