Confirmed here. sp7 on 15" MacBook Pro 1.83 running 10.4.6. gdb backtrace follows.

(gdb) where
#0 0x346ef41d in WebCore::setCookies ()
#1 0x345bbfd1 in WebCore::CSSStyleSelector::matchRulesForList ()
#2 0x345bc552 in WebCore::CSSStyleSelector::matchRules ()
#3 0x345d8593 in WebCore::CSSStyleSelector::styleForElement ()
#4 0x344895c2 in WebCore::ElementImpl::recalcStyle ()
#5 0x34489673 in WebCore::ElementImpl::recalcStyle ()
#6 0x34489673 in WebCore::ElementImpl::recalcStyle ()
#7 0x34489673 in WebCore::ElementImpl::recalcStyle ()
#8 0x34489673 in WebCore::ElementImpl::recalcStyle ()
#9 0x34489673 in WebCore::ElementImpl::recalcStyle ()
#10 0x34489673 in WebCore::ElementImpl::recalcStyle ()
#11 0x34489673 in WebCore::ElementImpl::recalcStyle ()
#12 0x34489673 in WebCore::ElementImpl::recalcStyle ()
#13 0x34489673 in WebCore::ElementImpl::recalcStyle ()
#14 0x34489673 in WebCore::ElementImpl::recalcStyle ()
#15 0x34557785 in WebCore::DocumentImpl::recalcStyle ()
#16 0x3455d9d2 in WebCore::DocumentImpl::updateStyleSelector ()
#17 0x345a8ea4 in WebCore::CSSStyleSheetImpl::insertRule ()
#18 0x345a8f81 in WebCore::CSSStyleSheetImpl::addRule ()
#19 0x3441bcd3 in KJS::DOMCSSStyleSheetProtoFunc::callAsFunction ()
#20 0x3432f9e6 in KJS::JSObject::call ()
#21 0x34322e8b in KJS::FunctionCallDotNode::evaluate ()
#22 0x34326ee7 in KJS::ExprStatementNode::execute ()
#23 0x3432703e in KJS::IfNode::execute ()
#24 0x34329a32 in KJS::SourceElementsNode::execute ()
#25 0x34326e09 in KJS::BlockNode::execute ()
#26 0x3430f9c7 in KJS::DeclaredFunctionImp::execute ()
#27 0x3430f44f in KJS::FunctionImp::callAsFunction ()
#28 0x3432f9e6 in KJS::JSObject::call ()
#29 0x343234a2 in KJS::FunctionCallResolveNode::evaluate ()
#30 0x34326ee7 in KJS::ExprStatementNode::execute ()
#31 0x34329b16 in KJS::SourceElementsNode::execute ()
#32 0x34326e09 in KJS::BlockNode::execute ()
#33 0x34329735 in KJS::TryNode::execute ()
#34 0x34329a32 in KJS::SourceElementsNode::execute ()
#35 0x34326e09 in KJS::BlockNode::execute ()
#36 0x3432703e in KJS::IfNode::execute ()
#37 0x34329a32 in KJS::SourceElementsNode::execute ()
#38 0x34326e09 in KJS::BlockNode::execute ()
#39 0x3430f9c7 in KJS::DeclaredFunctionImp::execute ()
#40 0x3430f44f in KJS::FunctionImp::callAsFunction ()
#41 0x3432f9e6 in KJS::JSObject::call ()
#42 0x3442cae2 in KJS::JSAbstractEventListener::handleEvent ()
#43 0x34555192 in WebCore::DocumentImpl::handleWindowEvent ()
#44 0x34561438 in WebCore::NodeImpl::dispatchGenericEvent ()
#45 0x34561983 in WebCore::NodeImpl::dispatchEvent ()
#46 0x34561cc6 in WebCore::NodeImpl::dispatchHTMLEvent ()
#47 0x3446d46a in WebCore::HTMLImageLoader::dispatchLoadEvent ()
#48 0x3455457d in WebCore::DocumentImpl::dispatchImageLoadEventsNow ()
#49 0x3470b4c8 in WebCore::setCookies ()
#50 0x3468b19e in WebCore::TimerBase::fireTimers ()
#51 0x3468b26c in WebCore::TimerBase::sharedTimerFired ()
#52 0x90823e8d in CFRunLoopRunSpecific ()
#53 0x90823179 in CFRunLoopRunInMode ()
#54 0x92ef9c5c in RunCurrentEventLoopInMode ()
#55 0x92ef929a in ReceiveNextEventCommon ()
#56 0x92ef91ba in BlockUntilNextEventMatchingListInMode ()
#57 0x9337aad1 in _DPSNextEvent ()
#58 0x9337a6be in -[NSApplication nextEventMatchingMask:untilDate:inMode:dequeue:] ()
#59 0x93374443 in -[NSApplication run] ()
#60 0x003c9773 in -[OAApplication run] ()
#61 0x93368397 in NSApplicationMain ()
#62 0x000297ac in main ()