This crossword No. 11251 clues and answers were published on Mon 29 May 2006 and the puzzle can be visited by following The Guardian Quick Crossword No. 11251 link.
All Across Clues and Answers:
1-across – Disco light : STROBE
4-across – Something dangerous, such as black ice? : HAZARD
9-across – Suffer : UNDERGO
10-across – Congregation : FLOCK
11-across – Story confirming innocence : ALIBI
12-across – Navigational aid : SEXTANT
13-across – Actress who is said to have said: I am a marvellous housekeeper. Every time I leave a man I keep his house : ZSAZSAGABOR
18-across – The Fens, perhaps : LOWLAND
20-across – Nervous : JUMPY
22-across – Opt – round : PLUMP
23-across – Get-together after some time apart : REUNION
24-across – Annoy – stinger : NETTLE
25-across – Rebellion : UNREST
All Down Clues and Answers:
1-down – Inform : SQUEAL
2-down – Half diameters : RADII
3-down – French composer, 1803-69 : BERLIOZ
5-down – Stick on : AFFIX
6-down – Heavily stoned fruit : AVOCADO
7-down – Former US territory, now divided into two states : DAKOTA
8-down – Basic : BOGSTANDARD
14-down – Shavings on the floor : SAWDUST
15-down – Postpone : ADJOURN
16-down – Attached like a bow tie, for example : CLIPON
17-down – Small pen, perhaps? : CYGNET
19-down – Shock : APPAL
21-down – Corn : MAIZE
This crossword has in total 26 where 13 are across and 13 are down.