a ton of rejected/stale hashes on btc guild

[heliosxx]

I just went to try BTC Guild since slush's was acting a bit weird for me. I've got 2 miners, one with about 330Mh/s and the other about 49Mh/s. The 49 one is getting something like 54% rejected:
[08/08/2011 00:56:18] Result: 5df198bc rejected        
[08/08/2011 00:57:10] Result: 878a55f1 rejected        
[08/08/2011 00:58:03] Result: a2caeda0 accepted        
[08/08/2011 00:58:41] Result: f6e734b4 rejected          
[08/08/2011 01:01:46] Result: 89f8bde5 rejected          
[08/08/2011 01:01:50] Result: 11f47493 rejected          
[08/08/2011 01:03:16] Result: 442823e8 rejected          
[08/08/2011 01:03:40] LP: New work pushed                
[08/08/2011 01:05:54] Result: 3d7843ef rejected          
[08/08/2011 01:06:27] Result: 6a6bffd3 rejected  

Using phoenix 1.5 poclbm. I tried a few setting changes, fastloop, worksize and aggression. Nothing changed the rejection rate, only the hashrate.
This is ubuntu, and I had a hell of a time getting it working (I still can't figure out how to OC the nvidia card without flashing the firmware), but it was working fine on slush and deepbit. My other miner's working fine, 0.5% rejected.

any ideas?

[JoelKatz]

Test against another pool. Rejected shares usually indicate something broken in your mining setup such as unreliable hardware. It's also possible that some proxy or NAT device is mangling your data.

[silverchair]

How's it going?

[heliosxx]

Test against another pool. Rejected shares usually indicate something broken in your mining setup such as unreliable hardware. It's also possible that some proxy or NAT device is mangling your data.

Yeah, already tried other pools, and have no problems there, that's why I'm not doubting my setup too much. Hardware isn't overclocked either.

[heliosxx]

How's it going?

not great:
192 (250, 56.56%)   192 (250, 56.56%)

192 accepted, 250 rejected.

[phr33]

I had similar problems, not as severe though. I was getting 5-7% rejects. I changed server to the uswest and the problem went away. This was some two weeks ago.

[heliosxx]

I had similar problems, not as severe though. I was getting 5-7% rejects. I changed server to the uswest and the problem went away. This was some two weeks ago.

I tried that as well, same result I'm afraid.