Adobe Reader users are occasionaly presented with Standard when published via Citrix XenApp 5.0

Question

We are publishing Adobe Standard to 4 users over 6 servers and have both Acrobat Standard and Reader installed on each Citrix server.  During installation of Standard, Reader was selected as the default application.
Regardless of this configuration, infrequently the Citrix servers will present Acrobat Standard to users that are not listed as users of the application.  So far, we have not noticed any patterns of behavior and have noted the following:
Although, all servers (1-6) have incorrectly presented Reader users with the Standard application at least once, only a few of the servers (1, 4, & 5) frequently violate the configuration settings;
Reader users and Standard users can coexist on the Citrix server and be presented the appropriate application (i.e. 5 reader users can be presented Reader and 5 Standard users can be presented Standard at the same time).
Citrix servers can present Acrobat Standard to Reader users even if there are no users of Standard accessing the server.
Users are starting to experience two types of failures:a. Acrobat fatally crashes with the following event:
Faulting application Acrobat.exe, version 9.2.0.124, time stamp 0x4ac7308f, faulting module unknown, version 0.0.0.0, time stamp 0x00000000, exception code 0xc0000005, fault offset 0x0c094e16, process id 0x2aa8, application start time 0x01caf2b4e54acde3.
       b. Adobe Reader will simply stop responding and error out when being accessed
Please submit any suggestions you might have for configuring these two applications to nicely coexist on a Citrix server.

Answer 1

Adobe Reader was installed and running on all Citrix servers since their inception over a year ago.
Recently, we installed Adobe Standard on each server and during installation Adobe Standard asked whether Reader or Standard should be used as the default program.  Adobe reader was selected and 80-85% of the time, the Citrix servers observe this rule.
On other occasions, when users with access to Reader open a PDF, Citrix will present Adobe Standard instead of the default program.  At first, I thought it might be caused by a user with Standard already open but further testing proved Adobe Standard can be presented to a user of Reader even if there is no open session of Standard.