Image Persistency problem

I've got a very strange behaviour of my image... It's all ok with Image Persistency on locally on my windows PC. But when I switch to it at hosting (it's webfactional.com with ubuntu) our site stops to answer (after saving the image, if I understand correctly). When I click on "snapshot" in "System Management" I get the following walkback in browser: Internal ErrorError: subscript is out of bounds: 2 MethodContext(Object)>>errorSubscriptBounds: MethodContext(ContextPart)>>at: MethodContext>>tempAt: [] in [] in WAWalkback>>renderStackFrame:on: Array(SequenceableCollection)>>withIndexDo: [] in WAWalkback>>renderStackFrame:on: BlockClosure>>renderOn: [] in WAGenericTag(WATagBrush)>>with: BlockClosure>>renderOn: WARenderCanvas(WACanvas)>>nest: WAGenericTag(WABrush)>>with: WAGenericTag(WATagBrush)>>with: WARenderCanvas(WAHtmlCanvas)>>definitionList: WAWalkback>>renderStackFrame:on: [] in [] in [] in WAWalkback>>renderStackOn: BlockClosure>>renderOn: [] in WAGenericTag(WATagBrush)>>with: BlockClosure>>renderOn: WARenderCanvas(WACanvas)>>nest: WAGenericTag(WABrush)>>with: Without any buttons, nor anything visible in Pharo (using VNC). But "Process Browser" shows no process for Seaside... How can I find the cause of the problem and/or fix it? -- Dennis Schetinin