thank you for your quick response. i indeed have a burner on the same channel as my hdd. i've read it is not a good option, but i've tried it (in windows only) but without a significant benefit. i use this setup, cause i have only one 80 wire ide cable, which is connected to disk. the other one is only 40 wire cable on which i have my old TEAC W54E. my lspci dump:

00:00.0 Host bridge: VIA Technologies, Inc. VT82C693A/694x [Apollo PRO133x] (rev 44)
00:01.0 PCI bridge: VIA Technologies, Inc. VT82C598/694x [Apollo MVP3/Pro133x AGP]
00:07.0 ISA bridge: VIA Technologies, Inc. VT82C596 ISA [Mobile South] (rev 21)
00:07.1 IDE interface: VIA Technologies, Inc. VT82C586/B/686A/B PIPC Bus Master IDE (rev 10)
00:07.2 USB Controller: VIA Technologies, Inc. USB (rev 0d)
00:07.3 Host bridge: VIA Technologies, Inc. VT82C596 Power Management (rev 30)
00:0a.0 USB Controller: OPTi Inc. 82C861 (rev 10)
00:0b.0 Multimedia video controller: Brooktree Corporation Bt878 Video Capture (rev 11)
00:0b.1 Multimedia controller: Brooktree Corporation Bt878 Audio Capture (rev 11)
00:0d.0 Multimedia audio controller: C-Media Electronics Inc CM8738 (rev 10)
01:00.0 VGA compatible controller: nVidia Corporation NV5 [RIVA TNT2/TNT2 Pro] (rev 15)

i use a swap partition of approx 250M. i noticed that when my buning is very slow, iowait is showing over 80 or 90%. disk activity is almost none. what causes it? could it be the burner and HDD on the same channel? i am sorry, but i don't know what exactly is "iowait"...