Script ignoring wait statement - Tera Term Ticket #39783 on OSDN

My TTL script ignores a wait statement at certain point of the script. In previous code parts, the wait statement sucessfully detects a certain string (VarRootPrompt is definded as 'root '). Find the code part below where the wait statement is simply ignored.

; execute OPK install
sendln 'opkg install package.opk'

; update timeout
timeout = 30


; wait till prompt is available
wait VarRootPrompt
if result=0 goto LABEL_TIMEOUT

; request execution state
sendln 'echo $?'

; wait for answer of Y_TCGx
wait '0' '1'

; check if execution is successful
if result=0 goto LABEL_TIMEOUT
if result=2 goto LABEL_TIMEOUT

The whole process is logged. The logfile content shows that the wait statement is simply ignored. The script sends "opkg install package.opk" and directly after that, without waiting for "root", sends "echo $?"

[root] tmp # opkg install package.opk
echo $?

exit
Installing xxx on root.
Configuring xxx.
[root] tmp # echo $?
0
[root] tmp # 
[root] tmp # exit

Can you explain this behaviour? Does the recognition of wait statements depend on something?