TTSCOMMIT error in Workflow

Hi,

We are running Dynamics AX 2009 Workflow, and have been experiencing stoppage in some of our workflows because of the following error:

Stopped (error): Stack trace: Call to TTSCOMMIT without first calling TTSBEGIN.

(S)\Classes\SysWorkflowWorkItemService\createWorkItems - line 164

The Workflow can proceed by clicking ‘Resume’ in Workflow history. There are no modifications within the class mentioned above, and I tried tracing the ttBegin and ttsCommit pairs but have found no mismatch.

Does anyone have an idea on this?