Downloading problem

Hi guys, need some help and I don't know where to find the answer because I've searched all over the net, as you can guess my problem is DOWNLOADING problem through Belkin N Wireless router, both WIRED or WIRELESS... Just found out yesterday when try to download something.

Current Situations:
- 1 month old Acer Aspire One Netbook (120Gb Version)
- Belkin N Wireless Router
- Windows XP Home SP3 (with all the updates installed)
- Latest Driver for both network devices (Wired & wireless)

Symptoms:
all browsing, chatting, but when it comes to downloading it always Stopped/error about 99%, resulting a corrupted files no matter which method I used. Tried limewire, tried opera, tried IE7. And this happen not just when downloading large files, it also happens when downloading small files like pictures attached to an email.

Solution Tried with no luck:
- Try with wired/wireless connection no luck
- updating every driver still no luck
- disabling the router & windows firewall still no luck
- put my ip in DMZ zone still no luck
- disable antivirus still no luck
- use both dynamic and static ip's still no luck

For comparison:
- The acer is used in the office with 3com switch for sharing internet WORK FLAWLESSLY always finish downloading...
- The router used with my brothers laptop (running B wifi) works fine when downloading...

so just as a thought:
Is there any problem with Windows xp home SP3 incompatibility? because right now I can't point to any of my stuff,
- can't blame the aspire coz it works flawlessly at the office
- can't blame the router coz it works with my brother's laptop

Your help would be greatly appreciated...

PS: Sorry if I post in the wrong section