Trigger on keys smtp_perf<25> http_perf<80>

[hpz]

Hello

I have some items with key smtp_perf<25> and http_perf<80>. When creating a trigger on one of this keys I get alwasy errors:

[ERROR:Cannot add trigger]
Expression [{siufsrv104:smtp_perf<25>.last(0)}] does not match to [server:key.func(param)]

Does anybody know how do I have to define correctly the key expression, or is this a bug?

Regards
Hans-Peter