SOLVED: Not able to record audio - track shows high sound

[tobbenos]

When pushing the record arm button on a track, I hear only a short noise (somewhat like when you unplug the cable from a guitar, just even shorter in duration). The track meter indicates that it receives a high, consistant (and non-changing) sound, although I cannot hear anything. The same is the case when recording. The track playlist shows a high, consistent sound, though nothing is put out.

I have tried both XLR and TRS inputs, DI and "normal", but the case remains the same.

When putting my Mbox2 to direct monitoring, I can hear what I want to record perfectly. Have I failed to spot the simple solution, or have I got a more severe matter?

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MacBook Pro 2.2 GHz
- 2 GB RAM
- Recording to Maxtor OneTouch III 500 GB FireWire External disk
- USB external disk attached for backup purposes, WD MyBook 250 GB
Digidesign Mbox2

[tobbenos]

As no answer was given me, I finally decided to reinstall Pro Tools. Now, everything is working perfectly, but I still do not know why it was like it was and what caused it..