Error in security - sale transaction

Hi,

Im facing issue in the below scenario.

1. Created a security class in FWZZ

2. Purchased 100 qty with above class in FTr_create.

3. Trying to sell 50 qty and Im facing below issue.

Short position in accounting code XXXX, val. area 001, ID No. XXXXXXXXXX, date
2012/12/10

1. Message
   no. TPM_TRL062

I have checked TPM26 and it is showing security positions of purchase transactions properly.

Recenrtly we are migrated from unix to Windows and I doubt this could be of infrastructure error.

Any help/suggestion is highly appriciated.

Thanks,

Venkat