I'm having the same problem.
When I put a CD in to be ripped, MC is unable to read and asks to reinsert CD.
When try again, still same problem.
I'm having the same problem since, version .213. If I restart MC it's able to read the CD and rip or play it.
The problem is still there in build .214
Media Center Registered 11.0.214 -- C:\Program\J River\Media Center 11\
Microsoft Windows XP Workstation 5.1 Service Pack 2 (Build 2600)
Intel Pentium 4 3173 MHz MMX / Memory: Total - 1047 MB, Free - 659 MB
Internet Explorer: 6.0.2900.2180 / ComCtl32.dll: 5.82 (xpsp_sp2_rtm.040803-2158) / Shlwapi.dll: 6.00.2900.2573 (xpsp_sp2_gdr.041130-1729) / Shell32.dll: 6.00.2900.2578 (xpsp_sp2_gdr.041130-1729) / wnaspi32.dll: N/A
Ripping / Drive E: HL-DT-STDVD-ROM GDR8162B Mode:Normal Type:Auto Speed:Max
Drive F: Mode:Normal Type:Auto Speed:Max
Digital playback: No / Use YADB: Yes / Get cover art: Yes / Calc replay gain: Yes / Copy volume: 32767
Eject after ripping: Yes / Play sound after ripping: No
Burning / Drive F: _NEC DVD+RW ND-1100A Addr: 1:1:0 Speed:16 MaxSpeed:16 BurnProof:Yes
Test mode: No / Eject after writing: Yes / Direct decoding: Yes / Write CD-Text: Yes
Use playback settings: No / Normalization: None