InCD causes insanely high CPU load while reading

Hi, I wonder if anybody else has this problem:
When reading data from a DVD+RW recorded with InCD (4.3.0.5 and all older versions I’ve tried) I get a CPU load over 70%!
There is no problem with the Drive (Ricoh MP5240A) or my DMA settings because IsoBuster can read the data without problems and low CPU usage.
I also tried a Toshiba 1712, exactly the same problem.

The worst part is not only the high CPU load, reading is also 2 times slower than IsoBuster!!!

Copying 347MB from DVD+RW to Harddisk
IsoBuster: 38sec
InCD: 75sec

The process wasting all the CPU time is InCDsrv.exe

My setup:
WinXP pro
Athlon Xp 2400
Elitegroup K7VTA3 V6 (VIA KT333 Chipset)