"Side"-simptoms:
While using skype there are hiccups on the calls every 1-2 minutes (that happened on Ubuntu 9.10 too).

It does not happen when I compile and use the "old" hal/madwifi-ng driver (neither on 9.10 nor 10.04) :-/

lspci -v:

0c:00.0 Ethernet controller: Atheros Communications Inc. AR5001 Wireless Network Adapter (rev 01)
	Subsystem: Atheros Communications Inc. Device 3063
	Flags: bus master, fast devsel, latency 0, IRQ 17
	Memory at efdf0000 (64-bit, non-prefetchable) [size=64K]
	Capabilities: [40] Power Management version 2
	Capabilities: [50] Message Signalled Interrupts: Mask- 64bit- Queue=0/0 Enable-
	Capabilities: [60] Express Legacy Endpoint, MSI 00
	Capabilities: [90] MSI-X: Enable- Mask- TabSize=1
	Capabilities: [100] Advanced Error Reporting <?>
	Capabilities: [140] Virtual Channel <?>
	Kernel driver in use: ath5k
	Kernel modules: ath5k


[ 5927.113556] ------------[ cut here ]------------
[ 5927.113590] WARNING: at /build/buildd/linux-2.6.32/drivers/net/wireless/ath/ath5k/base.c:1142 ath5k_tasklet_rx+0x4e0/0x5c0 [ath5k]()
[ 5927.113598] Hardware name: Latitude D430                   
[ 5927.113602] invalid hw_rix: 1b
[ 5927.113606] Modules linked in: cryptd aes_x86_64 aes_generic binfmt_misc ipt_MASQUERADE iptable_nat nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_state nf_conntrack ipt_REJECT xt_tcpudp iptable_filter ip_tables x_tables rfcomm sco bridge stp bnep l2cap kvm_intel kvm dm_crypt arc4 joydev snd_hda_codec_idt pcmcia snd_hda_intel snd_hda_codec snd_hwdep snd_pcm_oss snd_mixer_oss snd_pcm snd_seq_dummy snd_seq_oss snd_seq_midi snd_rawmidi snd_seq_midi_event snd_seq snd_timer snd_seq_device dell_wmi ath5k dell_laptop sdhci_pci mac80211 ath btusb bluetooth yenta_socket rsrc_nonstatic dcdbas pcmcia_core sdhci psmouse serio_raw snd ppdev cfg80211 led_class soundcore snd_page_alloc parport_pc lp parport fbcon tileblit font bitblit softcursor vga16fb vgastate usbhid hid usb_storage i915 drm_kms_helper ohci1394 ieee1394 tg3 intel_agp drm i2c_algo_bit video output
[ 5927.113759] Pid: 0, comm: swapper Not tainted 2.6.32-22-generic #36-Ubuntu
[ 5927.113764] Call Trace:
[ 5927.113770]  <IRQ>  [<ffffffff81066d0b>] warn_slowpath_common+0x7b/0xc0
[ 5927.113794]  [<ffffffff81066db1>] warn_slowpath_fmt+0x41/0x50
[ 5927.113811]  [<ffffffffa02b82a0>] ath5k_tasklet_rx+0x4e0/0x5c0 [ath5k]
[ 5927.113822]  [<ffffffff81540c45>] ? _spin_lock_irq+0x15/0x20
[ 5927.113833]  [<ffffffff8106c985>] tasklet_action+0xd5/0xe0
[ 5927.113841]  [<ffffffff8106e3a7>] __do_softirq+0xb7/0x1e0
[ 5927.113851]  [<ffffffff81031b52>] ? ack_apic_level+0x82/0x1f0
[ 5927.113861]  [<ffffffff810142ec>] call_softirq+0x1c/0x30
[ 5927.113868]  [<ffffffff81015cb5>] do_softirq+0x65/0xa0
[ 5927.113875]  [<ffffffff8106e245>] irq_exit+0x85/0x90
[ 5927.113883]  [<ffffffff81545ed5>] do_IRQ+0x75/0xf0
[ 5927.113891]  [<ffffffff81013b13>] ret_from_intr+0x0/0x11
[ 5927.113895]  <EOI>  [<ffffffff8130d347>] ? acpi_idle_enter_bm+0x28a/0x2be
[ 5927.113912]  [<ffffffff8130d340>] ? acpi_idle_enter_bm+0x283/0x2be
[ 5927.113923]  [<ffffffff81437537>] ? cpuidle_idle_call+0xa7/0x140
[ 5927.113933]  [<ffffffff81011e73>] ? cpu_idle+0xb3/0x110
[ 5927.113941]  [<ffffffff8153ad7b>] ? start_secondary+0xa8/0xaa
[ 5927.113947] ---[ end trace ff4aa9e332ecd6d7 ]---