Thanks Jungly, that might have been the case.
When a:c notified ATC of problem they were still at low level in climbout from ZRH. When Reims called us to inform about the problem a/c was at FL220 for traffic, then climbed to FL260. Then after 5 to 10 minutes requested FL300. All seemed normal speed/roc wise. Even with the accountants in mind, would you have continued if the problem occured during climbout?