I get the same exact error message after just downloading the newest version. Here's my info ...
Media Center Registered 9.1.305 -- C:\Program Files\J River\Media Jukebox\
Microsoft Windows 98 SE
Intel Pentium III 599 MHz MMX / Memory: Total - 130 MB, Free - 47 MB
Resource Info: System - 74 %, GDI - 85 %, User - 74 %
Internet Explorer: 6.0.2800.1106 / ComCtl32.dll: 5.81 / Shlwapi.dll: 6.00.2800.1276 / Shell32.dll: 4.72.3812.600 / wnaspi32.dll: 2, 0, 0, 0 , ASPI for WIN32 DLL, Copyright © Adaptec 1995 / Aspi32.sys: N/A
Ripping / Drive D: Copy mode:Normal CD Type:Auto Read speed:Max
Drive E: Copy mode:Normal CD Type:Auto Read speed:Max
Digital playback: Yes / Use YADB: Yes / Get cover art: No / Calc replay gain: No / Copy volume: 32767
Eject after ripping: No / Play sound after ripping: No
Burning / Drive E: SONY CD-RW CRX140E Addr: 0:1:0 Speed:8 MaxSpeed:8 BurnProof:No
Test mode: No / Eject after writing: No / Direct decoding: No / Write CD-Text: No
Use playback settings: No / Normalization: None