Im not sure if this will help out, but i found these lines in my log:
2008-06-10 10:40:16,531 DEBUG CalemPdo - Transaction committed by CalemDbo.update@384
2008-06-10 10:40:16,531 DEBUG CalemAclGroupDbo - Reload cache for acl_group
2008-06-10 10:40:16,531 DEBUG CalemPDOStatement - Query time:0.0002, the query=select * from acl_group, params=NULL
2008-06-10 10:40:16,531 DEBUG CalemPdo - Rollback called by CalemDataLoader.updateRecord@111 , transaction stack=
2008-06-10 10:40:16,531 ERROR installation - Error at CalemInstDbSetupController.validateInput: There is no active transaction