its normal for it to happen a little its not normal for it to happen with no accepted's in between for like 20-30 min straight....
Post your recent shifts and what you are using to mine. Below is what a single R9 290 looks like.
Recent Shifts
ID Ended Shares (yours / total) Blocks Found
10512 OPEN 4096 / 139229687 9
10511 2014-03-09 05:12:12 2048 / 152319482 5
10510 2014-03-09 05:06:17 3584 / 151316988 4
10509 2014-03-09 05:00:27 6144 / 153913843 9
10508 2014-03-09 04:54:12 4096 / 151040502 7
10507 2014-03-09 04:48:17 5632 / 152060915 9
10506 2014-03-09 04:42:22 6144 / 150095861 12
10505 2014-03-09 04:36:27 4096 / 151059961 5
10504 2014-03-09 04:30:32 2560 / 153342460 4
10503 2014-03-09 04:24:32 3584 / 151335418 6