JVM 1.3.1 strange behaviour of GC

[Thomas Heinlein]

running an application on a jvm 1.3.1.06.
After hours and days some gc eat up 6 ... 9 seconds - this is not acceptable because it pauses the application.

Typically GC log output is like shown below.
Very soon after start up a gc due to 'permanent generation full' (reason code 2) occurs. After this the JVM sets the 'tenuring threshold' to 1 - i.e. shorter living objects will be held in the 'old generation' instead of the 'from-to-space'.

Playing with -Xmn and -Xmx does not really help.

GC-Log:
< -1="" 59.463284="" 3="" 32="" 1="" 5177344="" 0="" 5177344="" 350928="" 534704="" 589824="" 376904="" 653088="" 12779520="" 4558424="" 4558424="" 4718592="" 0.063356="">
< -1="" 70.785285="" 4="" 144="" 32="" 5177344="" 0="" 5177344="" 534704="" 165848="" 589824="" 653088="" 892256="" 12779520="" 4561656="" 4561656="" 4718592="" 0.019210="">
< -1="" 80.332370="" 5="" 16="" 32="" 5177344="" 0="" 5177344="" 165848="" 197112="" 589824="" 892256="" 892256="" 12779520="" 4653568="" 4653568="" 4718592="" 0.020556="">
< -1="" 94.799315="" 6="" 32768="" 1="" 5177344="" 0="" 5177344="" 197112="" 465496="" 589824="" 892256="" 892256="" 12779520="" 4813328="" 4813328="" 4980736="" 0.027914="">
< 2="" 108.395498="" 1="" 32="" 1="" 4099008="" 0="" 5308416="" 465496="" 0="" 589824="" 892256="" 2030008="" 12779520="" 5242856="" 5242856="" 5242880="" 0.483750="">
< -1="" 119.774172="" 7="" 24="" 1="" 5308416="" 0="" 5308416="" 0="" 589824="" 589824="" 2030008="" 2282056="" 12779520="" 5987888="" 5987888="" 6033408="" 0.144979="">
< -1="" 139.944646="" 8="" 24="" 1="" 5308416="" 0="" 5308416="" 589824="" 545744="" 589824="" 2282056="" 2842488="" 12779520="" 6078888="" 6078888="" 6295552="" 0.086992="">
< -1="" 172.785804="" 9="" 1176="" 1="" 5308416="" 0="" 5308416="" 545744="" 589824="" 589824="" 2842488="" 4043880="" 12779520="" 6405920="" 6405920="" 6557696="" 0.137688="">
< -1="" 185.064664="" 10="" 24="" 1="" 5308416="" 0="" 5308416="" 589824="" 589824="" 589824="" 4043880="" 5870200="" 12779520="" 6546264="" 6546264="" 6557696="" 0.120687="">
< -1="" 193.711850="" 11="" 16400="" 1="" 5308416="" 0="" 5308416="" 589824="" 589824="" 589824="" 5870200="" 7850384="" 12779520="" 6547192="" 6547192="" 6557696="" 0.092901="">