assuming that you are in a stratum pool try to set variable difficulty at 64 to 66, i am not sure about the exact number though :p
Where do I set that?
it's usually in the registration of your worker at the pool you use that you can set the initial value, but as far as I understand the pool will adjust according to your work results. So it should only have an impact on the first activities
By the way, these are the numbers I'm getting from btcguild:
[SUMMARY] =>
(
[0] => SUMMARY
[Elapsed] => 69956
[MHS av] => 71381.83
[Found Blocks] => 0
[Getworks] => 2573
[Accepted] => 36271
[Rejected] => 150
[Hardware Errors] => 815
[Utility] => 31.11
[Discarded] => 4786
[Stale] => 0
[Get Failures] => 0
[Local Work] => 1223915
[Remote Failures] => 0
[Network Blocks] => 144
[Total MH] => 4993602159.0807
[Work Utility] => 1001.57
[Difficulty Accepted] => 1160672.00000000
[Difficulty Rejected] => 4800.00000000
[Difficulty Stale] => 0.00000000
[Best Share] => 1430374
)