Hi,
I'm using Leadtek Winfast DTV Dongle (STK7700P based) (ID 0413:6f00). It worked like a charm in 2.6.31, but then I switched to 2.6.34 and it's not working.

When I try to tune a channel from kaffeine (or dvbscan), the process becomes defunct and kernel throws following output:

[  807.165881] Pid: 10638, comm: kaffeine Tainted: P           2.6.34-gentoo #2 M4A87TD EVO/System Product Name
[  807.165882] RIP: 0010:[<ffffffff8134ef30>]  [<ffffffff8134ef30>] i2c_transfer+0x21/0xc4
[  807.165885] RSP: 0018:ffff8800c5607b08  EFLAGS: 00010292
[  807.165887] RAX: ffff8800c5607b68 RBX: 0000000000000002 RCX: 0000000000000000
[  807.165888] RDX: 0000000000000002 RSI: ffff8800c5607b48 RDI: 0000000000000002
[  807.165889] RBP: ffff8800c5607b38 R08: 000000000e008d80 R09: ffff880005803360
[  807.165891] R10: ffff8800058033c0 R11: dead000000200200 R12: 00000000ffffffa1
[  807.165892] R13: ffff8800b4c78800 R14: 0000000000000001 R15: 0000000000000002
[  807.165894] FS:  00007f60eed91740(0000) GS:ffff880001e40000(0000) knlGS:0000000000000000
[  807.165895] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[  807.165896] CR2: 0000000000000012 CR3: 00000000c543b000 CR4: 00000000000006e0
[  807.165898] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  807.165899] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[  807.165901] Process kaffeine (pid: 10638, threadinfo ffff8800c5606000, task ffff880005577080)
[  807.165902] Stack:
[  807.165903]  ffff8800c5607b48 00000000000000eb 0000000000000001 ffff8800b4c78800
[  807.165905] <0> 0000000000000001 ffffc90012795000 ffff8800c5607b98 ffffffffa050210d
[  807.165907] <0> ffff00020000000c ffff8800c5607b78 000000020001000c ffff8800c5607b68
[  807.165909] Call Trace:
[  807.165913]  [<ffffffffa050210d>] dib7000p_read_word+0x68/0xb7 [dib7000p]
[  807.165916]  [<ffffffff813139a9>] ? usb_submit_urb+0x359/0x37a
[  807.165918]  [<ffffffffa0502f67>] dib7000p_pid_filter_ctrl+0x27/0x85 [dib7000p]
[  807.165925]  [<ffffffffa0528174>] stk70x0p_pid_filter_ctrl+0x14/0x18 [dvb_usb_dib0700]
[  807.165928]  [<ffffffffa03140e8>] dvb_usb_ctrl_feed+0xcf/0x118 [dvb_usb]
[  807.165930]  [<ffffffffa031414c>] dvb_usb_start_feed+0xe/0x12 [dvb_usb]
[  807.165936]  [<ffffffffa02b87ef>] dmx_ts_feed_start_filtering+0x74/0xc4 [dvb_core]
[  807.165940]  [<ffffffffa02b5a04>] dvb_dmxdev_start_feed+0xc4/0xf0 [dvb_core]
[  807.165945]  [<ffffffffa02b6bde>] dvb_dmxdev_filter_start+0x2af/0x317 [dvb_core]
[  807.165949]  [<ffffffffa02b6ef2>] ? dvb_dmxdev_add_pid+0x54/0xf1 [dvb_core]
[  807.165953]  [<ffffffffa02b7202>] dvb_demux_do_ioctl+0x273/0x4c1 [dvb_core]
[  807.165956]  [<ffffffff811f6e29>] ? avc_has_perm+0x4e/0x60
[  807.165960]  [<ffffffffa02b5398>] dvb_usercopy+0xe0/0x149 [dvb_core]
[  807.165964]  [<ffffffffa02b6f8f>] ? dvb_demux_do_ioctl+0x0/0x4c1 [dvb_core]
[  807.165967]  [<ffffffff810e82aa>] ? do_filp_open+0x553/0x5c8
[  807.165971]  [<ffffffffa02b5ffb>] dvb_demux_ioctl+0x10/0x12 [dvb_core]
[  807.165973]  [<ffffffff810e9d3c>] vfs_ioctl+0x72/0x9e
[  807.165975]  [<ffffffff810ea257>] do_vfs_ioctl+0x474/0x4b5
[  807.165977]  [<ffffffff810ea2ed>] sys_ioctl+0x55/0x77
[  807.165981]  [<ffffffff81002a6b>] system_call_fastpath+0x16/0x1b
[  807.165982] Code: eb 34 81 e8 e3 d9 f6 ff c9 c3 55 48 89 e5 41 57 41 89 d7 41 56 41 55 41 54 41 bc a1 ff ff ff 53 48 89 fb 48 83 ec 08 48 89 75 d0 <48> 8b 47 10 48 83 38 00 0f 84 86 00 00 00 65 48 8b 04 25 48 b5 
[  807.165998] RIP  [<ffffffff8134ef30>] i2c_transfer+0x21/0xc4
[  807.166000]  RSP <ffff8800c5607b08>
[  807.166001] CR2: 0000000000000012
[  807.166002] ---[ end trace a1d8e41b25b7f44b ]---
[  807.166008] kaffeine used greatest stack depth: 4040 bytes left

I tried to google a little and found this: https://patchwork.kernel.org/patch/101784/

I believe it's the same issue as mine. I tried the mentioned workaround (disabling pid filtering) and it helped. I can watch TV again, however EPG is not working.