Adobe Illustrator CS4 very slow to open/use in student setting

Hello all. We have students running Adobe CS4 with mobile accounts on 10.5.6 machines. The performance of CS4 opening at times, and during use is super slow, unusable. The lab is on its own separate subnet, and there are about 30 machines. There is an xServe that ONLY manages these machines, no others as these are the only Macs in the school. The network itself is less than 2 years old, the network itself is running top notch. Its not a speed issue. They are 2 year old silver iMacs. They were working fine, then with more use, they slowed up using Adobe CS 4 apps. All other applications etc are working normally. There have been no new updates or changes.

To anyone that has had experience using CS4 in a Mobile account student setting. Please try and help me out.