PC Remote Control problem!

Hi everyone,

I have been building this Home theater PC for the living room based on old components. I've also build an Infra Red receiver circuit which is connected through COM2 to this PC. I use PC Remote Control (4.0.208 i think version). It works great, it recognizes the commands from the remote control but when i use a dvd software player (like windvd or powerdvd) the system finds it really hard to recognize any commands.
I used powerdvd 5 and windvd 4.5 recorder and it couldn't get any commands (like pause, fwd, etc). I must press remote control button for quite long for it to see the command and then it recognizes wrong. Same if i play Quake3 or an emulator (mame,psx) and want to lower the sound or mute. It looks like the CPU and memory usage is holding it back.
I installed Windvd 4 and the signal recognitions is quite better now, but after some time the system resources almost runs out (like 13% and even less). I haven't got anything else running except Windvd and Remote control.
It seems that the CPU and memory usage when an application like windvd running, is holding PC Remote Control back but it drains all the resources of the system out. I'm running this PC under Win98. Is there a way so that i could allocate system memory/resources somehow to this certain programm so that it won't drain out all the system resources? Could Windows XP handle this better?
Is it this software that is causing this or the Serial Port?Any help or suggestion would be much appreciated!

Thanks in advance.

System:
PIII-933Mhz
mobo Gigabyte GA-BX2000 (BX440 chipset)
320 MB RAM (PC133)
Hercules 3D Prophet II Titanium (Geforce2 Titanium 64MB)
HDD Quantum Fireball 6.4 GB
Sony DVD-Rom / Creative SoundBlaster 128PCI
Windows 98 (not SE)