It is probably not the majority of the problem but it is an issue. My store is now down due to the use of mybitcoin for a payment gateway. Luckily I lost no money there as I always had it on auto-forward to my own wallet, but it did provide me a service.
Currently I have to run my store manually which has resulted in no orders. While the store was going through mybitcoin.com we had a regular flow of customers and bitcoin.
I have contacted two payment providers about a new opencart plugin for bitcoin and both were responsive and are 'working on it'
Hopefully there will be someone who gets something up soon, as when it is harder to use bitcoin, they are less desirable. I am open to re-doing my whole store in another platform if necessary but was hoping to continue to use the work I have already put into opencart.