Rendering Problem in Premiere Pro 1.5

Hi,
My computer specs are as follows:

AMD Athlon 64 2800+
512MB RAM 400FSB
80GB SATA HDD

I have been using PPRO 1.5 for quite a long time and satisfactorily. Recently, I had to format my computer and reinstalled PPRO 1.5 again. After that whenever I try to export the edited video to Adobe Media Encoder and opt for VCD High Quality Encoding , it gives me asn error massege after 3-4% [of a 65min video] rendering is completed.
The error massege is as follows:

"Failed to Return the Video Frame, cancelling the process"

I encoded the same video within PPRO using Main Concept MPEG encoder 1.06, and it was rendered perfectly, though time taken was about 6hrs, which is abnormal for a 65min video encoded to VCD. Though I do not prefer to use 3rd party encoders.

I have reqired update KB886716 installed. And I have updated the integrated encoder PPRO to 1.1 according to Adobe FAQ.

None of these problems were there with my previous installation.

So could someone lease help me? And need that desparately.

Thank you.