More jumping buses

Hi everyone, this is my first post but I have looked around the forum to try and find an answer but can't. I'm having the same problem as many of you - the jumping buses! It only seems to happen on the Berlin-Spandau map at the depot. The Grundorf map works fine.

I've tried the different settings that other people have suggested but it makes no difference. My PC specs are:

Dell Dimension 9150
Dual-Core Pentium D 3.0 GHZ
2GB RAM
2GB XFX ATI Radeon HD 5570 Graphics Card
Windows XP Professional (SP3)

It's a shame because I love this game but I can only drive on the Grundorf map at the moment

Has anyone else had the problem and managed to fix it?

It must surely be a problem with the game if it's affecting so many people who all have PC's over the minimum specification?

I had the jumping bus problem. On other threats is put suggestions: select level computer: 2006 or minimum, but your computer level is good, mine single P4 3 ghz, 1,5 gb ram, ati 3450 agp connection 512 mb drivers updated, windows xp.
Disabled reflections (mirrors), down resolution level and other details. With my computer level runs well and has less level that yours. Only get jumping bus, changing line from green icon. Then when loads sim, well, select bus and begins to jumpl. I have to go out game, and load it of new to play it well without jumpings...

Your Spanish friend, Carlos