If you’re using Citrix Presentation Server v4.5 environment and you are using two monitors, you might have problems dragging some of all application to your second monitor.
When working with multi-monitor Citrix ICA sessions, it is very important to calculate the amount of ICA session graphics required.
This is the memory allocated to each session for its graphics data and it is set to the default of 5120 bytes and limited to 8192 bytes in the Access Management Console. It is possible to have a virtual desktop whose session graphics memory is larger than the maximum amount assigned in the Access Management Console. When such an event occurs, either the color depth or resolution will be automatically reduced, based on the settings in the Citrix Access Management Console.
Here’s how you can change the amount of available ICA session graphic.
In the left pane of the Citrix Access Management Console, select the farm and in the task pane, click Modify
Select Server Properties > Modify all properties > Server Default > ICA > Display
Set the Maximum memory to use for each session’s graphics setting to a large enough size (in kilobytes), preferably to 8192, to incorporate the entire virtual desktop. If this setting is not high enough, the seamless application is restricted to the subset of the monitors that fits within the size specified.