I apologise for troubling you with my problem. As I can see on the forum that you had similar problems when first synchronising Calendar entries I believe you may know the solution. I have recently changed our system from Outlook to Lotus Notes and am only able to synchronise the mails and To DOs with my P900. Before all options have been working perfectly for me with outlook.
I can see that to solve your calendar sync problem you had to delete all calendar entries first from the P900. Then you performed sync and it was working well. Is it the same case with Contacts? Do I have to also delete all contacts and calendar entries in the Lotus Notes or only on the P900? Please let me know your views on this as it is very annoying problem!
Best regards and have a great day! You can also send me a mail to firstname.lastname@example.org