4.2.5 + ZenPack + custom panel + "Site error"

Hello,

I'm using a custom panel entry for my device in the left pane like this:

name="testMenu"
for="..MyDevice.MyDevice"
template="templates/testMenu.pt"
permission="zenoss.View"
/>

testMenu.pt contains (apart from others):

tabindex="-1"
style="height:30px;width:136px;text-align:center;"
onclick="resetVariable()"
class="tableheader"
id="resetVariableButton" />

Obviously I have a

def manage_resetVariable(self, optInOut=False, optInOutMetrics=False, REQUEST=None)
&& security.declareProtected('Manage DMD','manage_resetVariable') in MyDevice.

However when I click on the "Reset Variable" button I get a "Site error" issue, nothing fancy can be seen
in any of the logs.
Any idea how to track this

Thanks,