Strange error after server problems.

Hello,

   Lenya has been installed before half year . All this time it has working
perfectly. Until server naturally was run out of memory. It was not memory
leak, only too much information. We increased hosting plan and after this
strange error related to page envelope input module apeared:

Caused by: org.apache.cocoon.sitemap.PatternException: Cannot get
variable 'document-lastmodified' in expression
'{date-iso8601-rfc822:{page-envelope:document-lastmodified}}'
	at org.apache.cocoon.components.treeprocessor.variables.PreparedVariableResolver.processModule(PreparedVariableResolver.java:280)
	at org.apache.cocoon.components.treeprocessor.variables.PreparedVariableResolver.resolve(PreparedVariableResolver.java:209)
	at org.apache.cocoon.components.treeprocessor.variables.VariableResolver.buildParameters(VariableResolver.java:107)
	at org.apache.cocoon.components.treeprocessor.sitemap.ActTypeNode.invoke(ActTypeNode.java:95)
	at org.apache.cocoon.components.treeprocessor.AbstractParentProcessingNode.invokeNodes(AbstractParentProcessingNode.java:47)
	at org.apache.cocoon.components.treeprocessor.sitemap.ActTypeNode.invoke(ActTypeNode.java:139)
	at org.apache.cocoon.components.treeprocessor.AbstractParentProcessingNode.invokeNodes(AbstractParentProcessingNode.java:47)
	at org.apache.cocoon.components.treeprocessor.sitemap.MatchNode.invoke(MatchNode.java:108)
	at org.apache.cocoon.components.treeprocessor.AbstractParentProcessingNode.invokeNodes(AbstractParentProcessingNode.java:69)
	at org.apache.cocoon.components.treeprocessor.sitemap.PipelineNode.invoke(PipelineNode.java:143)
	at org.apache.cocoon.components.treeprocessor.AbstractParentProcessingNode.invokeNodes(AbstractParentProcessingNode.java:69)
	at org.apache.cocoon.components.treeprocessor.sitemap.PipelinesNode.invoke(PipelinesNode.java:93)
	at org.apache.cocoon.components.treeprocessor.ConcreteTreeProcessor.process(ConcreteTreeProcessor.java:235)
	at org.apache.cocoon.components.treeprocessor.ConcreteTreeProcessor.process(ConcreteTreeProcessor.java:177)
	at org.apache.cocoon.components.treeprocessor.TreeProcessor.process(TreeProcessor.java:254)
	at org.apache.cocoon.components.treeprocessor.sitemap.MountNode.invoke(MountNode.java:118)
	... 41 more

All exception text you can see in source of
http://www.lmps.lt/lenya/lmps/live/naujienos.html page.

It seams that request input into parameter "document-lastmodified" of
page-envelope is empty and not good. How can I fix this?



Thanks,
Gintare