The amount of physical memory available to applications (Sybase IQ) is displayed under Physical Memory (K). If the Available value is consistently below 5000 it is possible the physical memory for the machine is overallocated. This is because at the 5000(K) mark, Windows produces page faults in order to maintain a minimum of 5MB of free memory.
To monitor physical memory, from the Task Manager applet, select the Performance tab.