Interactive Brokers and Dividends

I think there a few people here who use IBKR, and I was wondering what their experience of receiving dividends has been like, particularly dividends from the London Stock Exchange.  My experience has been disappointing.  Dividends are rarely received on the pay date, but are often days or even weeks late.  I have repeatedly raised this with them, but they just say that they pay the dividends when they receive them.  (My other brokers, Internaxx (Luxembourg) and Saxo (Singapore), invariably pay out on the correct day.)

The one case I've been able to pin them down on is where they'd failed to provide the registrar with their bank account details, so the dividend was paid by cheque.

Am I just unlucky, or are they really incompetent in dividend processing? And is it typical of them not to care about what is clearly a significant issue?