Block erupters and Raspberry Pi problem

[maud138]

I had two block erupters running on a Raspberry Pi with cgminer 3.1.1. (with a powered hub). All worked fine.
Then I received two new block erupters and I added them to the powered hub. It all worked.
After a while one of the first block erupters was giving a lot of HW errors and all the block erupters stopped working every now and then.
I thought the block erupter was broken. I took it out and tried it on my desktop with cgminer 3.3.4 It worked fine and also the other three on the Raspberry Pi started working fine again.

What can I do now? I want all four of them on my Raspberry Pi. Should I update cgminer to 3.3.4? I read somewhere that the newer versions of cgminer don't work well with a Raspberry Pi.

And how is it possible that one block erupter can determine the working of the other three?

Thanks for your replies

[HellDiverUK]

You're running out of power on your hub.

[maud138]

Can you give me a tip what hub I should use?