Citrix plugin can't find the server

I have installed citrix web and xenapp plugins on a number of machines.
For some reason on one of our remote branches the users are having difficulties connecting to our citrix iis servers.

Usually, first thing in the morning when they login to their machines their xenapp plugin kicks in and tries to log to the config.xml site in order to display the apps published to them, soon after this they have the message that the citrix server cannot be contacted, although this server can be pinged, no problem.
The way around it I found is to open a web browser and type http://citrix-iis-servername, once the page opens their xenapp plugin can now contact the server and the apps are all there.
Why is this happening?, why the web plugin is activating the xenapp plugin?
why only to this branch?

any ideas?

(citrix servers are XenApp 5.0, plugins are XenApp v11, servers OS are 2008 x64bit)

Thanks in advance for your help
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I suggest removing both Citrix clients and reinstalling the Xenapp Plugin (version 11). See if it works better then.
txarli33Author Commented:
I have done that.
I have also tried upgrading to xenapp plugin v12, same result.

Installing only the online plugin right?
txarli33Author Commented:
I've found the problem.
it was related to a firewall on the remote site.
this firewall was checking the connection's authentication every hour and so disconnecting it regularly.
that's why when connecting via a browser to the ctx site it would reconnect the pnagent and carry on working.

I wasn't aware of this firewall that's why i didn't mention it.

thanks for your help but i think i found my own solution

thanks again

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