x51v ActiveSync problems with USB cable

[Ches]

After struggling with ActiveSync problem on my business laptop I found a new aspect of sync problem when using USB cable.

History: I used to have issues with establishing the reliable ActiveSync connection of my x51v and Compaq laptop at the office (at home after a couple of days troubleshooting session everything works fine). One day everything works fine, next days I cannot sync, then everything is again OK and so on.

What I identified during all this experimenting really amazed me. If the PPC is completely charged (more, than 85%) everything works just fine. If PPC is half charged (approximately 50%) I can still charge the device, but the connection (and oviously ActiveSync) is not working. So if I wait and charge the device to 85% I can Active Sync. When Dell is seriously discharged (about 35% or less) I can neither charge nor ActiveSync (the device is discharging if left on when connected.

I think this is due to some pretty variations in how manufacturers follow the standard of USB port (power at the first place), because the same cable works fine with my home laptop.

FYI, this happened with the gear:
- USB cable from Belkin (bought from Dell with handheld)
- Compaq Presario M2105CA laptop

Before that I had some issues with USB on Toshiba laptops when using some gadgets, but they were not so wierd.