Rekordbox E8302 and E8309 errors

0) Have you read the "READ ME FIRST" thread in its entirety AND TRIED THE SOLUTIONS THERE before posting: yes, i've already tried 4 of the proposed actions.

1) Operating System: ASUS laptop with windows 7

2) OS Type: 64bit

3) rekordbox version: 3.1.0.

4) Using LINK: Yes

** 4a) LINK Connection method*: DJM2000 Nexus with HUB, wired

* 4b) Using with CDJs**: Yes, CDJ 2000 Nexus, firmware: Ver 1.22 (latest)

5a) Does the device have multiple partitions: yes, second partition D:/ on my laptop

6) Have you scanned your files for errors: Yes, with MP3checker, but I use also MP4 (ITunes)

7) Have you scanned your drive for errors: Yes

8) Is rekordbox crashing at all: No

** 8a) If crashing, is it resulting in*: error message: E8302 en E8309: sometimes CDJ2000 doesn't accept brand new mp4 or older mp3, sometimes it crashes while playing.

* 8b) If not crashing, are there any error messages*: E8302 and E8309

**9) Are you able to repeat / reproduce the problem: Yes, each time when I play the same song.

* 9a) If yes, can you do it consistently*: Yes

**10) Does the problem occur with one specific song: Yes, with older and with new songs (brand new iTunes fe.)*

10a) If yes, please post a link to it: ?

11) Any other notes regarding your setup only: no

12) Provide as much detail of the issue here: latop: Intel core duo CPU, 2,13 GHz RAM: 4 G

I manage about 22.000 songs in rekordbox. Perhaps this is too much, but then again I need Rekordbox to 'manage' that amount of numbers. While playing a gig, the CDJ crashes several times, each time while playing the same tracks. Perhaps cause the track is corrupted, but it often happens with brand new MP4's, fresh downloaded from ITunes. I leave them as MP4 (AAC format) as a salesman told me that a AAC format is much more stronger than mp3's. Also some old mp3's crashes sometimes. When I play the same songs with an external Hard Disk, no problem occurs.

According to me, it has something to do with the performance of my laptop or the amount of songs, or something in rekordbox?