a few weeks back I ran into some communication failures and high reject numbers at BTCGuild after a LP-change
I escalated the problem to Eleuthria https://bitcointalksearch.org/topic/m.839599 and he said he would contact you about it
Apparently the problem doesn't come up with everyone just with low-latency miners and pools with Poolservj running
I'm running into the same problems with Clipse's pool but have NO problems when mining on Deepbit for instance (tried out a lot of different pools in the last few days)
I submitted CGMiner output on BTCGuild here https://bitcointalksearch.org/topic/m.839444
and this is the output from Clipse's pool
cgminer version 2.3.1 - Started: [2012-04-14 04:56:26]
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(5s):583.9 (avg):321.3 Mh/s | Q:2867 A:2263 R:105 HW:4 E:79% U:4.18/m
TQ: 2 ST: 2 SS: 6 DW: 267 NB: 66 LW: 5131 GF: 12 RF: 21
Connected to http://pool.bonuspool.co.cc:80 with LP as user XXXXX
Block: 000007211c0c28968da77075f714da8e... Started: [13:51:09]
--------------------------------------------------------------------------------
[P]ool management [G]PU management [S]ettings [D]isplay options [Q]uit
GPU 0: 76.0C 2574RPM | 324.4/321.3Mh/s | A:2263 R:105 HW:4 U:4.18/m I: 4
--------------------------------------------------------------------------------
[2012-04-14 13:56:21] Accepted 00000000.77b43c68.4d7bec56 GPU 0 thread 0 pool 0
[2012-04-14 13:56:30] Accepted 00000000.c2bb7890.abfddea3 GPU 0 thread 0 pool 0
[2012-04-14 13:56:31] Accepted 00000000.80051067.164ef42f GPU 0 thread 0 pool 0
[2012-04-14 13:56:49] Accepted 00000000.4c40ecfa.9643c5b7 GPU 0 thread 0 pool 0
[2012-04-14 13:56:57] longpoll failed for http://pool.bonuspool.co.cc:80/LP, sle
eping for 30s
[2012-04-14 13:57:02] Pool 0 communication failure, caching submissions
[2012-04-14 13:57:07] Pool 0 communication resumed, submitting work
[2012-04-14 13:57:07] Rejected 00000000.a53bea12.3d3ea9c4 GPU 0 thread 0 pool 0
[2012-04-14 13:57:38] Rejected 00000000.daff5e55.77bcdd04 GPU 0 thread 0 pool 0
[2012-04-14 13:57:39] longpoll failed for http://pool.bonuspool.co.cc:80/LP, sle
eping for 30s
[2012-04-14 13:57:41] Pool 0 communication failure, caching submissions
I hope you can make sense of it and I am curious if others are having the same problems....